Found 7442 Articles for Java

How to print a byte array in Java?

seetha
Updated on 24-Feb-2020 11:18:02

18K+ Views

You can simply iterate the byte array and print the byte using System.out.println() method.Examplepublic class Tester {    public static void main(String[] args) {       byte[] a = { 1,2,3};       for(int i=0; i< a.length ; i++) {          System.out.print(a[i] +" ");       }    } }Output1 2 3

how to shuffle a 2D array in java correctly?

vanithasree
Updated on 24-Feb-2020 11:17:13

1K+ Views

Yes. Create a list to represent a 2D array and then use Collections.shuffle(list).Exampleimport java.util.ArrayList; import java.util.Collections; import java.util.List; public class Tester {    public static void main(String[] args) {       List rows = new ArrayList();       rows.add(new int[]{1,2,3});       rows.add(new int[]{4,5,6});       rows.add(new int[]{7,8,9});       System.out.println("Before Shuffle");       System.out.println("[0][0] : " + rows.get(0)[0]);       System.out.println("[1][1] : " + rows.get(1)[1]);       System.out.println("After Shuffle");       Collections.shuffle(rows);       System.out.println("[0][0] : " + rows.get(0)[0]);       System.out.println("[1][1] : " + rows.get(1)[1]);    } }OutputBefore Shuffle [0][0] : 1 [1][1] : 5 After Shuffle [0][0] : 7 [1][1] : 2

how to initialize a dynamic array in java?

radhakrishna
Updated on 24-Feb-2020 11:16:20

575 Views

Following program shows how to initialize an array declared earlier.Examplepublic class Tester {    int a[];    public static void main(String[] args) {       Tester tester = new Tester();       tester.initialize();    }    private void initialize() {       a = new int[3];       a[0] = 0;       a[1] = 1;       a[2] = 2;       for(int i=0; i< a.length ; i++) {          System.out.print(a[i] +" ");       }    } }Output0 1 2

How to concatenate byte array in java?

mkotla
Updated on 30-Jul-2019 22:30:21

3K+ Views

You ByteArrayOutputStream to write byte arrays and get the result using its toByteArray() method.import java.io.ByteArrayOutputStream; import java.io.IOException; public class Tester { public static void main(String[] args) throws IOException { byte[] a = { 1,2,3}; byte[] b = { 4,5,6}; ByteArrayOutputStream baos = new ByteArrayOutputStream(); baos.write(a); baos.write(b); byte[] c = baos.toByteArray(); for(int i=0; i< c.length ; i++){ System.out.print(c[i] +" "); } } }Output1 2 3 4 5 6

How to create a dynamic 2D array in Java?

Giri Raju
Updated on 24-Feb-2020 11:15:24

3K+ Views

If you wish to create a dynamic 2d array in Java without using List. And only create a dynamic 2d array in Java with normal array then click the below linkYou can achieve the same using List. See the below program. You can have any number of rows or columns.Exampleimport java.util.ArrayList; import java.util.List; public class Tester {    public static void main(String[] args) {       List rows = new ArrayList();       rows.add(new int[]{1, 2, 3});       rows.add(new int[]{1, 2});       rows.add(new int[]{1});       //get element at row : 0, column ... Read More

How to remove an element from an array in Java

Sreemaha
Updated on 24-Feb-2020 11:11:49

1K+ Views

Following example shows how to remove an element from array. Exampleimport java.util.ArrayList; public class Main {    public static void main(String[] args) {       ArrayList objArray = new ArrayList();       objArray.clear();       objArray.add(0,"0th element");       objArray.add(1,"1st element");       objArray.add(2,"2nd element");       System.out.println("Array before removing an element"+objArray);       objArray.remove(1);       objArray.remove("0th element");       System.out.println("Array after removing an element"+objArray);    } }OutputThe above code sample will produce the following result. Array before removing an element[0th element, 1st element, 2nd element] Array after removing an element[2nd element]

How can I clear or empty a StringBuilder in Java.

mkotla
Updated on 24-Feb-2020 12:21:39

3K+ Views

You can either setLength to be 0 or create a new StringBuilder() instance. See the example below −Examplepublic class Tester {    public static void main(String[] args) {       StringBuilder builder = new StringBuilder();       builder.append("sample");       System.out.println(builder.toString());       builder.setLength(0);       System.out.println(builder.toString());       builder.append("sample");       System.out.println(builder.toString());    } }Outputsample sample

Difference between declaring a variable before or in a Java loop.

Giri Raju
Updated on 30-Jul-2019 22:30:21

125 Views

Performance wise, there is hardly any difference. But it is good to keep a variable local to the scope it is used. So declaring a variable inside Java loop is generally preferred.

How to convert List to int[] in Java?

Sreemaha
Updated on 30-Jul-2019 22:30:21

953 Views

You can simply iterate through list and fill the array as shown below −import java.util.ArrayList; import java.util.List; public class Tester {    public static void main(String[] args) {       List list = new ArrayList();       list.add(new Integer(1));       list.add(new Integer(2));       list.add(new Integer(3));       list.add(new Integer(4));       int[] array = new int[list.size()];       for(int i=0;i

How to pass a function as a parameter in Java

Prabhas
Updated on 17-Jun-2020 11:36:16

5K+ Views

Yes. From Java 8 onwards, we can do so using method references.Method references help to point to methods by their names. A method reference is described using "::" symbol. A method reference can be used to point the following types of methods −Static methodsInstance methodsConstructors using new operator (TreeSet::new)Method Reference ExampleCreate the following Java program using any editor of your choice in, say, C:\> JAVA.Java8Tester.java Live Demo import java.util.List; import java.util.ArrayList; public class Java8Tester {    public static void main(String args[]) {       List names = new ArrayList(); names.add("Mahesh");       names.add("Suresh");       names.add("Ramesh");       ... Read More

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