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Zwykle tablica jest zbiorem elementów podobnego typu, które mają ciągłą lokalizację w pamięci.

Tablica Java to obiekt zawierający elementy o podobnym typie danych. Ponadto elementy tablicy są przechowywane w ciągłej lokalizacji pamięci. Jest to struktura danych, w której przechowujemy podobne elementy. W tablicy Java możemy przechowywać tylko ustalony zestaw elementów.

Tablica w Javie jest oparta na indeksach, pierwszy element tablicy jest przechowywany pod indeksem 0, drugi element pod indeksem pierwszym i tak dalej.

W przeciwieństwie do C/C++ długość tablicy możemy uzyskać za pomocą elementu długości. W C/C++ musimy użyć operatora sizeof.

W Javie tablica jest obiektem klasy generowanej dynamicznie. Tablica Java dziedziczy klasę Object i implementuje interfejsy Serializable i Cloneable. W Javie możemy przechowywać prymitywne wartości lub obiekty w tablicy. Podobnie jak w języku C/C++, w Javie możemy również tworzyć tablice jednowymiarowe lub wielowymiarowe.

Co więcej, Java udostępnia funkcję anonimowych tablic, która nie jest dostępna w C/C++.

Zalety

Optymalizacja kodu:Dzięki temu kod jest zoptymalizowany, możemy efektywnie pobierać lub sortować dane.Losowy dostęp:Możemy uzyskać dowolne dane znajdujące się na pozycji indeksu.

Niedogodności

Limit rozmiaru:Możemy przechowywać tylko stały rozmiar elementów w tablicy. Nie zwiększa swojego rozmiaru w czasie wykonywania. Aby rozwiązać ten problem, w Javie zastosowano framework kolekcji, który rośnie automatycznie.

Rodzaje tablic w Javie

Istnieją dwa typy tablic.

• Tablica jednowymiarowa
• Tablica wielowymiarowa

Tablica jednowymiarowa w Javie

Składnia deklarowania tablicy w Javie

klasa abstrakcyjna w Javie

 dataType[] arr; (or) dataType []arr; (or) dataType arr[]; 

Tworzenie instancji tablicy w Javie

 arrayRefVar=new datatype[size]; 

Przykład tablicy Java

Zobaczmy prosty przykład tablicy Java, w którym będziemy deklarować, tworzyć instancje, inicjować i przeglądać tablicę.

 //Java Program to illustrate how to declare, instantiate, initialize //and traverse the Java array. class Testarray{ public static void main(String args[]){ int a[]=new int[5];//declaration and instantiation a[0]=10;//initialization a[1]=20; a[2]=70; a[3]=40; a[4]=50; //traversing array for(int i=0;i <a.length;i++) length is the property of array system.out.println(a[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 20 70 40 50 </pre> <hr> <h2>Declaration, Instantiation and Initialization of Java Array</h2> <p>We can declare, instantiate and initialize the java array together by:</p> <pre> int a[]={33,3,4,5};//declaration, instantiation and initialization </pre> <p>Let&apos;s see the simple example to print this array.</p> <pre> //Java Program to illustrate the use of declaration, instantiation //and initialization of Java array in a single line class Testarray1{ public static void main(String args[]){ int a[]={33,3,4,5};//declaration, instantiation and initialization //printing array for(int i=0;i <a.length;i++) length is the property of array system.out.println(a[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 33 3 4 5 </pre> <h2>For-each Loop for Java Array</h2> <p>We can also print the Java array using <strong> <a href="/java-each-loop-enhanced">for-each loop</a> </strong> . The Java for-each loop prints the array elements one by one. It holds an array element in a variable, then executes the body of the loop.</p> <p>The syntax of the for-each loop is given below:</p> <pre> for(data_type variable:array){ //body of the loop } </pre> <p>Let us see the example of print the elements of Java array using the for-each loop.</p> <pre> //Java Program to print the array elements using for-each loop class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; //printing array using for-each loop for(int i:arr) System.out.println(i); }} </pre> <p>Output:</p> <pre> 33 3 4 5 </pre> <hr> <h2>Passing Array to a Method in Java</h2> <p>We can pass the java array to method so that we can reuse the same logic on any array.</p> <p>Let&apos;s see the simple example to get the minimum number of an array using a method.</p> <pre> //Java Program to demonstrate the way of passing an array //to method. class Testarray2{ //creating a method which receives an array as a parameter static void min(int arr[]){ int min=arr[0]; for(int i=1;iarr[i]) min=arr[i]; System.out.println(min); } public static void main(String args[]){ int a[]={33,3,4,5};//declaring and initializing an array min(a);//passing array to method }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> 3 </pre> <h2>Anonymous Array in Java</h2> <p>Java supports the feature of an anonymous array, so you don&apos;t need to declare the array while passing an array to the method.</p> <pre> //Java Program to demonstrate the way of passing an anonymous array //to method. public class TestAnonymousArray{ //creating a method which receives an array as a parameter static void printArray(int arr[]){ for(int i=0;i <arr.length;i++) system.out.println(arr[i]); } public static void main(string args[]){ printarray(new int[]{10,22,44,66}); passing anonymous array to method }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 22 44 66 </pre> <h2>Returning Array from the Method</h2> <p>We can also return an array from the method in Java.</p> <pre> //Java Program to return an array from the method class TestReturnArray{ //creating method which returns an array static int[] get(){ return new int[]{10,30,50,90,60}; } public static void main(String args[]){ //calling method which returns an array int arr[]=get(); //printing the values of an array for(int i=0;i <arr.length;i++) system.out.println(arr[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 30 50 90 60 </pre> <h2>ArrayIndexOutOfBoundsException</h2> <p>The Java Virtual Machine (JVM) throws an ArrayIndexOutOfBoundsException if length of the array in negative, equal to the array size or greater than the array size while traversing the array.</p> <pre> //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread &apos;main&apos; java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let&apos;s see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" system.out.print(arr[i][j]+' '); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+' '); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { &apos;d&apos;, &apos;e&apos;, &apos;c&apos;, &apos;a&apos;, &apos;f&apos;, &apos;f&apos;, &apos;e&apos;, &apos;i&apos;, &apos;n&apos;, &apos;a&apos;, &apos;t&apos;, &apos;e&apos;, &apos;d&apos; }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println(&apos;Printing original array:&apos;); for(int i:arr) System.out.println(i); System.out.println(&apos;Printing clone of the array:&apos;); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println(&apos;Are both equal?&apos;); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let&apos;s see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+' '); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let&apos;s see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+' '); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){></pre></arr.length;i++)></pre></arr.length;i++)></pre></a.length;i++)></pre></a.length;i++)>

Deklaracja, tworzenie instancji i inicjalizacja tablicy Java

Możemy wspólnie zadeklarować, utworzyć instancję i zainicjować tablicę Java poprzez:

 int a[]={33,3,4,5};//declaration, instantiation and initialization 

Zobaczmy prosty przykład wydrukowania tej tablicy.

 //Java Program to illustrate the use of declaration, instantiation //and initialization of Java array in a single line class Testarray1{ public static void main(String args[]){ int a[]={33,3,4,5};//declaration, instantiation and initialization //printing array for(int i=0;i <a.length;i++) length is the property of array system.out.println(a[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 33 3 4 5 </pre> <h2>For-each Loop for Java Array</h2> <p>We can also print the Java array using <strong> <a href="/java-each-loop-enhanced">for-each loop</a> </strong> . The Java for-each loop prints the array elements one by one. It holds an array element in a variable, then executes the body of the loop.</p> <p>The syntax of the for-each loop is given below:</p> <pre> for(data_type variable:array){ //body of the loop } </pre> <p>Let us see the example of print the elements of Java array using the for-each loop.</p> <pre> //Java Program to print the array elements using for-each loop class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; //printing array using for-each loop for(int i:arr) System.out.println(i); }} </pre> <p>Output:</p> <pre> 33 3 4 5 </pre> <hr> <h2>Passing Array to a Method in Java</h2> <p>We can pass the java array to method so that we can reuse the same logic on any array.</p> <p>Let&apos;s see the simple example to get the minimum number of an array using a method.</p> <pre> //Java Program to demonstrate the way of passing an array //to method. class Testarray2{ //creating a method which receives an array as a parameter static void min(int arr[]){ int min=arr[0]; for(int i=1;iarr[i]) min=arr[i]; System.out.println(min); } public static void main(String args[]){ int a[]={33,3,4,5};//declaring and initializing an array min(a);//passing array to method }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> 3 </pre> <h2>Anonymous Array in Java</h2> <p>Java supports the feature of an anonymous array, so you don&apos;t need to declare the array while passing an array to the method.</p> <pre> //Java Program to demonstrate the way of passing an anonymous array //to method. public class TestAnonymousArray{ //creating a method which receives an array as a parameter static void printArray(int arr[]){ for(int i=0;i <arr.length;i++) system.out.println(arr[i]); } public static void main(string args[]){ printarray(new int[]{10,22,44,66}); passing anonymous array to method }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 22 44 66 </pre> <h2>Returning Array from the Method</h2> <p>We can also return an array from the method in Java.</p> <pre> //Java Program to return an array from the method class TestReturnArray{ //creating method which returns an array static int[] get(){ return new int[]{10,30,50,90,60}; } public static void main(String args[]){ //calling method which returns an array int arr[]=get(); //printing the values of an array for(int i=0;i <arr.length;i++) system.out.println(arr[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 30 50 90 60 </pre> <h2>ArrayIndexOutOfBoundsException</h2> <p>The Java Virtual Machine (JVM) throws an ArrayIndexOutOfBoundsException if length of the array in negative, equal to the array size or greater than the array size while traversing the array.</p> <pre> //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread &apos;main&apos; java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let&apos;s see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" system.out.print(arr[i][j]+\' \'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\' \'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { &apos;d&apos;, &apos;e&apos;, &apos;c&apos;, &apos;a&apos;, &apos;f&apos;, &apos;f&apos;, &apos;e&apos;, &apos;i&apos;, &apos;n&apos;, &apos;a&apos;, &apos;t&apos;, &apos;e&apos;, &apos;d&apos; }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println(&apos;Printing original array:&apos;); for(int i:arr) System.out.println(i); System.out.println(&apos;Printing clone of the array:&apos;); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println(&apos;Are both equal?&apos;); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let&apos;s see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\' \'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let&apos;s see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\' \'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){></pre></arr.length;i++)></pre></arr.length;i++)></pre></a.length;i++)>

Dla każdej pętli dla tablicy Java

Możemy również wydrukować tablicę Java za pomocą dla każdej pętli . Pętla Java for-each wypisuje elementy tablicy jeden po drugim. Przetrzymuje element tablicy w zmiennej, a następnie wykonuje treść pętli.

Poniżej podano składnię pętli for-each:

 for(data_type variable:array){ //body of the loop } 

Zobaczmy przykład wydruku elementów tablicy Java przy użyciu pętli for-each.

 //Java Program to print the array elements using for-each loop class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; //printing array using for-each loop for(int i:arr) System.out.println(i); }} 

Wyjście:

 33 3 4 5 

Przekazywanie tablicy do metody w Javie

Możemy przekazać tablicę Java do metody, abyśmy mogli ponownie użyć tej samej logiki w dowolnej tablicy.

Zobaczmy prosty przykład uzyskania minimalnej liczby tablicy za pomocą metody.

 //Java Program to demonstrate the way of passing an array //to method. class Testarray2{ //creating a method which receives an array as a parameter static void min(int arr[]){ int min=arr[0]; for(int i=1;iarr[i]) min=arr[i]; System.out.println(min); } public static void main(String args[]){ int a[]={33,3,4,5};//declaring and initializing an array min(a);//passing array to method }} 

Wyjście:

 3 

Tablica anonimowa w Javie

Java obsługuje funkcję anonimowej tablicy, więc nie trzeba deklarować tablicy podczas przekazywania tablicy do metody.

 //Java Program to demonstrate the way of passing an anonymous array //to method. public class TestAnonymousArray{ //creating a method which receives an array as a parameter static void printArray(int arr[]){ for(int i=0;i <arr.length;i++) system.out.println(arr[i]); } public static void main(string args[]){ printarray(new int[]{10,22,44,66}); passing anonymous array to method }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 22 44 66 </pre> <h2>Returning Array from the Method</h2> <p>We can also return an array from the method in Java.</p> <pre> //Java Program to return an array from the method class TestReturnArray{ //creating method which returns an array static int[] get(){ return new int[]{10,30,50,90,60}; } public static void main(String args[]){ //calling method which returns an array int arr[]=get(); //printing the values of an array for(int i=0;i <arr.length;i++) system.out.println(arr[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 30 50 90 60 </pre> <h2>ArrayIndexOutOfBoundsException</h2> <p>The Java Virtual Machine (JVM) throws an ArrayIndexOutOfBoundsException if length of the array in negative, equal to the array size or greater than the array size while traversing the array.</p> <pre> //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread &apos;main&apos; java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let&apos;s see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" system.out.print(arr[i][j]+\' \'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\' \'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { &apos;d&apos;, &apos;e&apos;, &apos;c&apos;, &apos;a&apos;, &apos;f&apos;, &apos;f&apos;, &apos;e&apos;, &apos;i&apos;, &apos;n&apos;, &apos;a&apos;, &apos;t&apos;, &apos;e&apos;, &apos;d&apos; }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println(&apos;Printing original array:&apos;); for(int i:arr) System.out.println(i); System.out.println(&apos;Printing clone of the array:&apos;); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println(&apos;Are both equal?&apos;); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let&apos;s see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\' \'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let&apos;s see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\' \'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){></pre></arr.length;i++)></pre></arr.length;i++)>

Zwracana tablica z metody

Tablicę możemy również zwrócić z metody w Javie.

 //Java Program to return an array from the method class TestReturnArray{ //creating method which returns an array static int[] get(){ return new int[]{10,30,50,90,60}; } public static void main(String args[]){ //calling method which returns an array int arr[]=get(); //printing the values of an array for(int i=0;i <arr.length;i++) system.out.println(arr[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 30 50 90 60 </pre> <h2>ArrayIndexOutOfBoundsException</h2> <p>The Java Virtual Machine (JVM) throws an ArrayIndexOutOfBoundsException if length of the array in negative, equal to the array size or greater than the array size while traversing the array.</p> <pre> //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread &apos;main&apos; java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let&apos;s see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" system.out.print(arr[i][j]+\' \'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\' \'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { &apos;d&apos;, &apos;e&apos;, &apos;c&apos;, &apos;a&apos;, &apos;f&apos;, &apos;f&apos;, &apos;e&apos;, &apos;i&apos;, &apos;n&apos;, &apos;a&apos;, &apos;t&apos;, &apos;e&apos;, &apos;d&apos; }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println(&apos;Printing original array:&apos;); for(int i:arr) System.out.println(i); System.out.println(&apos;Printing clone of the array:&apos;); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println(&apos;Are both equal?&apos;); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let&apos;s see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\' \'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let&apos;s see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\' \'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){></pre></arr.length;i++)>

Wyjątek ArrayIndexOutOfBounds

Wirtualna maszyna Java (JVM) zgłasza wyjątek ArrayIndexOutOfBoundsException, jeśli długość tablicy jest ujemna, równa rozmiarowi tablicy lub większa niż rozmiar tablicy podczas przechodzenia przez tablicę.

 //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread &apos;main&apos; java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let&apos;s see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" system.out.print(arr[i][j]+\' \'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\' \'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { &apos;d&apos;, &apos;e&apos;, &apos;c&apos;, &apos;a&apos;, &apos;f&apos;, &apos;f&apos;, &apos;e&apos;, &apos;i&apos;, &apos;n&apos;, &apos;a&apos;, &apos;t&apos;, &apos;e&apos;, &apos;d&apos; }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println(&apos;Printing original array:&apos;); for(int i:arr) System.out.println(i); System.out.println(&apos;Printing clone of the array:&apos;); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println(&apos;Are both equal?&apos;); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let&apos;s see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\' \'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let&apos;s see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\' \'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){>

Tablica wielowymiarowa w Javie

W takim przypadku dane są przechowywane w indeksie opartym na wierszach i kolumnach (znanym również jako forma macierzowa).

Składnia deklarowania tablicy wielowymiarowej w Javie

 dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; 

Przykład tworzenia instancji tablicy wielowymiarowej w Javie

 int[][] arr=new int[3][3];//3 row and 3 column 

Przykład inicjowania tablicy wielowymiarowej w Javie

 arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; 

Przykład wielowymiarowej tablicy Java

Zobaczmy prosty przykład deklarowania, tworzenia instancji, inicjowania i drukowania tablicy 2Dimensional.

 //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" system.out.print(arr[i][j]+\\' \\'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\\' \\'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { &apos;d&apos;, &apos;e&apos;, &apos;c&apos;, &apos;a&apos;, &apos;f&apos;, &apos;f&apos;, &apos;e&apos;, &apos;i&apos;, &apos;n&apos;, &apos;a&apos;, &apos;t&apos;, &apos;e&apos;, &apos;d&apos; }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println(&apos;Printing original array:&apos;); for(int i:arr) System.out.println(i); System.out.println(&apos;Printing clone of the array:&apos;); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println(&apos;Are both equal?&apos;); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let&apos;s see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\\' \\'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let&apos;s see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\\' \\'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){>

Postrzępiona tablica w Javie

Jeśli tworzymy nieparzystą liczbę kolumn w tablicy 2D, nazywa się to tablicą postrzępioną. Inaczej mówiąc, jest to tablica tablic o różnej liczbie kolumn.

 //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\\' \\'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { &apos;d&apos;, &apos;e&apos;, &apos;c&apos;, &apos;a&apos;, &apos;f&apos;, &apos;f&apos;, &apos;e&apos;, &apos;i&apos;, &apos;n&apos;, &apos;a&apos;, &apos;t&apos;, &apos;e&apos;, &apos;d&apos; }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println(&apos;Printing original array:&apos;); for(int i:arr) System.out.println(i); System.out.println(&apos;Printing clone of the array:&apos;); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println(&apos;Are both equal?&apos;); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let&apos;s see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\\' \\'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let&apos;s see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\\' \\'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;>

Jaka jest nazwa klasy tablicy Java?

W Javie tablica jest obiektem. Dla obiektu array tworzona jest klasa proxy, której nazwę można uzyskać za pomocą metody getClass().getName() na obiekcie.

 //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} 

Wyjście:

 I 

Kopiowanie tablicy Java

Tablicę do innej możemy skopiować za pomocą metody arraycopy() klasy System.

Składnia metody arraycopy

 public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) 

Przykład kopiowania tablicy w Javie

 //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } 

Wyjście:

 caffein 

Klonowanie tablicy w Javie

Ponieważ tablica Java implementuje interfejs Cloneable, możemy utworzyć klon tablicy Java. Jeśli utworzymy klon tablicy jednowymiarowej, utworzy się głęboka kopia tablicy Java. Oznacza to, że skopiuje rzeczywistą wartość. Jeśli jednak utworzymy klon tablicy wielowymiarowej, utworzy się płytka kopia tablicy Java, co oznacza, że ​​skopiuje odniesienia.

 //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} 

Wyjście:

och, Java

 Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false 

Dodanie 2 macierzy w Javie

Zobaczmy prosty przykład, który dodaje dwie macierze.

 //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\\' \\'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let&apos;s see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\\' \\'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){>

Mnożenie 2 macierzy w Javie

W przypadku mnożenia macierzy jednorzędowy element pierwszej macierzy mnoży się przez wszystkie kolumny drugiej macierzy, co można zrozumieć na poniższym obrazku.

Zobaczmy prosty przykład mnożenia dwóch macierzy składających się z 3 wierszy i 3 kolumn.

 //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j&lt;3;j++){" c[i][j]="0;" k="0;k&lt;3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\\' \\'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd &amp; even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){>

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