Found 9150 Articles for Object Oriented Programming

what is the simplest way to print a java array

Johar Ali
Updated on 24-Feb-2020 10:34:41

124 Views

To make things simple, convert the array to list and then print it.Exampleimport java.util.Arrays; import java.util.List; public class Tester {    public static void main(String[] args) {       Integer[] numbers = {1,2,3,4,5};       List list = Arrays.asList(numbers);       System.out.println(list);    } }Output[1,2,3,4,5]

How to create a subarray from another array in Java

Kumar Varma
Updated on 24-Feb-2020 10:42:51

18K+ Views

Use Arrays.copyOfRange() method to get a subarray.Exampleimport java.util.Arrays; public class Tester {    public static void main(String[] args) {       int[] array = new int[] {1, 2, 3, 4, 5};       int[] subArray = Arrays.copyOfRange(array, 0, 2);       System.out.println("Array: ");       for(int i = 0; i < array.length; i++) {          System.out.print(array[i] + " ");       }       System.out.println("Sub array: ");       for(int i = 0; i < subArray.length; i++) {          System.out.print(subArray[i] + " ");       }    } }OutputArray: 1 2 3 4 5 Sub array: 1 2

Removal of negative numbers from an array in Java

Rama Giri
Updated on 24-Feb-2020 10:41:59

763 Views

Following program shows how to remove negative numbers from an array.Exampleimport java.util.ArrayList; import java.util.Iterator; import java.util.List; public class Tester {    public static void main(String[] args) {       List objArray = new ArrayList();       objArray.clear();       objArray.add(2);       objArray.add(-3);       objArray.add(4);       System.out.println("Array before removing an element "+objArray);       Iterator iterator = objArray.iterator();                while(iterator.hasNext()) {          Integer next = iterator.next();          if(next < 0) {             iterator.remove();          }       }       System.out.println("Array after removing an element"+objArray);    } }OutputArray before removing an element [ 2, -3, 4 ] Array after removing an element [ 2, 4 ]

how can I declare an Object Array in Java?

Arjun Thakur
Updated on 24-Feb-2020 10:41:06

299 Views

Array of Object class can be created which can accept any type of object. During operation on such array, instanceof operator can be used.Examplepublic class Tester {    public static void main(String[] args) {       Object[] dataArray = new Object[3];       dataArray[0] = new Integer(0);       dataArray[1] = new String("1");       dataArray[2] = new Boolean(false);       for(Object data: dataArray) {          if(data instanceof Integer) {             System.out.println(((Integer) data).intValue());          }          if(data instanceof String) {             System.out.println(data);          }          if(data instanceof Boolean) {             System.out.println(((Boolean) data).booleanValue());          }       }    } }Output0 1 false

Converting ArrayList to String[] in java

Fendadis John
Updated on 24-Feb-2020 10:28:51

478 Views

Following program is converting an ArrayList to String[];Exampleimport java.util.ArrayList; import java.util.List; public class Tester {    public static void main(String[] args) {       List names = new ArrayList();       names.add("A");       names.add("B");       names.add("C");       String[] nameArray = names.toArray(new String[names.size()]);       for(String name: nameArray) {          System.out.println(name);       }    } }OutputA B C

how to convert vector to string array in java

Fendadis John
Updated on 24-Feb-2020 10:40:14

385 Views

Following program converts a vector into a array of String.Exampleimport java.util.Vector; public class Tester {    public static void main(String[] args) {       Vector data = new Vector();       data.add("A");       data.add("B");       data.add("C");       String[] strObjects = data.toArray(new String[data.size()]);       for(String obj: strObjects) {          System.out.println(obj);       }    } }

how to convert Object array to String array in java

Sai Nath
Updated on 30-Jul-2019 22:30:21

5K+ Views

As list.toArray() returns an Object[], it can be converted to String array by passing the String[] as parameter. See the example below.import java.util.ArrayList; import java.util.List; public class Tester { public static void main(String[] args) { List data = new ArrayList(); data.add("A"); data.add("B"); data.add("C"); //Object[] objects = data.toArray(); String[] strObjects = data.toArray(new String[0]); for(String obj: strObjects) { System.out.println(obj); } } }OutputA B C

Convert bytes to a string in java

seetha
Updated on 24-Feb-2020 10:26:35

612 Views

Use String(byte[]) constructor to convert byte[] to String.Examplepublic class Tester {    public static void main(String[] args) {       String test = "I love learning Java";       byte[] bytes = test.getBytes();       String converted = new String(bytes);       System.out.println(converted);    } }OutputI love learning Java

The most elegant ways to iterate the words of a java string.

Sreemaha
Updated on 24-Feb-2020 10:25:38

3K+ Views

Just split the string based on space and then iterate it. See the example below −Examplepublic class Tester {    public static void main(String[] args) {       String test = "I love learning Java";       String[] subStrings = test.split(" ");       for(String subString: subStrings) {          System.out.println(subString);       }    } }OutputI love learning Java

Loop through an array in Java

radhakrishna
Updated on 24-Feb-2020 10:19:29

276 Views

Following example shows how to loop through an array using a foreach loop.public class Tester {    public static void main(String[] args) {       int[] dataArray = {1, 2, 3, 4};       for(int i: dataArray) {          System.out.println(i);       }    } }

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