Found 9326 Articles for Object Oriented Programming

Yes, break statement can be used in nested for loops. It works on the for loop in which it is applied. See the example below.Examplepublic class Tester {    public static void main(String[] args) {       for(int i = 0; i< 2; i++) {          for(int j = 0; j < 2; j++){             if(i == 1) {                break;             }             System.out.println("i = " + i+",j = " + j);          }       }    } }

Use List.clear() method to empty an array.Exampleimport java.util.ArrayList; import java.util.List; public class Tester {    public static void main(String[] args) {       List list = new ArrayList();       list.add("A");       list.add("B");       list.add("C");       list.add("D");       list.add("E");       list.add("F");       list.add("G");       list.add("H");       System.out.println("Original List " + list);       list.clear();       System.out.println("Cleared List " + list);    } }OutputOriginal List [A, B, C, D, E, F, G, H] Cleared List []

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

Following example uses Contains method to search a String in the Array.Exampleimport java.util.ArrayList; public class Main {    public static void main(String[] args) {    ArrayList objArray = new ArrayList();    ArrayList objArray2 = new ArrayList();    objArray2.add(0, "common1"); objArray2.add(1, "common2");   objArray2.add(2, "notcommon"); objArray2.add(3, "notcommon1");    objArray.add(0, "common1"); objArray.add(1, "common2");    System.out.println("Array elements of array1"+objArray);    System.out.println("Array elements of array2"+objArray2);    System.out.println("Array 1 contains String common2?? " +objArray.contains("common1"));    System.out.println("Array 2 contains Array1?? " +objArray2.contains(objArray) );     }  }OutputThe above code sample will produce the following result.Array elements of array1[common1, common2] Array elements of array2[common1, common2, notcommon, notcommon1] Array ... Read More

Exampleclass Shape{     private String shapeName;     private int numSides;      Shape(String shapeName, int numSides){         this.shapeName = shapeName;         this.numSides = numSides;     }     public String toString(){         return shapeName + " has " + numSides + " sides.";     } } class ObjectList{     private Object[] list = new Object[10];     private int numElement = 0;      public void add(Object next){         list[numElement] = next;         numElement++;     }      @Override     public String toString(){         String str="";         int i=0;         while(list[i] != null){             str += list[i]+"";             i++;         }         return str;     } } public class Driver{     public static void main(String[] args){         ObjectList list = new ObjectList();         Shape square = new Shape("square", 4);         Shape hex = new Shape("hexagon", 6);         list.add(hex);         list.add(square);         System.out.println(list);     } }

You can use List.removeAll() method to filter an array. exampleimport java.util.ArrayList; import java.util.List; public class Tester {    public static void main(String[] args) {       List list = new ArrayList();       list.add("A");       list.add("B");       list.add("C");       list.add("D");       list.add("E");       list.add("F");       list.add("G");       list.add("H");       List filters = new ArrayList();       filters.add("D");       filters.add("E");       filters.add("F");       System.out.println("Original List " + list);       list.removeAll(filters);       System.out.println("Filtered List ... Read More

Use Integer.toString(int, redix) where int is byte to be converted and redix is 16 for hexadecimal format.

Following example helps to determine the upper bound of a two dimensional array with the use of arrayname.length.https://www.tutorialspoint.com/javaexamples/arrays_upperbound.htm

Following program shows how to declare a static string array.Examplepublic class Tester {    private static String[] array;    static {       array = new String[2];       array[0] = "Hello";       array[1] = "World";    }    public static void main(String[] args) {       System.out.println("Array: ");       for(int i = 0; i < array.length; i++){       System.out.print(array[i] + " ");       }    } }OutputArray: Hello World

A method may also return an array. For example, the following method returns an array that is the reversal of another array -Examplepublic static int[] reverse(int[] list) {    int[] result = new int[list.length];    for (int i = 0, j = result.length - 1; i < list.length; i++, j--) {       result[j] = list[i];    }    return result; }