The Object class is the superclass of every single class in Java. This position implies that every class in Java, even if a built-in class or function like String or a user-defined one, directly or indirectly inherits from Object. Understanding the Object Class The Object class provides fundamental methods that every Java object inherits. Even if a class does not explicitly extend another class, it implicitly extends Object. Below is a demostration of the same − class Example { //This class implicitly extends to an Object } Why Does Every Class Inherit from ... Read More

You can remove an element from the JSONArray object using the remove() method. This method accepts an integer and removes the element in that particular index.Exampleimport org.json.JSONArray; public class RemoveFromJsonArray {    public static void main(String args[]) throws Exception {       String [] myArray = {"JavaFX", "HBase", "JOGL", "WebGL"};       JSONArray jsArray = new JSONArray();       for (int i=0; i < myArray.length; i++) {          jsArray.put(myArray[i]);      }      System.out.println(jsArray);      jsArray.remove(3);      System.out.println("After deleting ::"+jsArray);    } }Output["JavaFX","HBase","JOGL","WebGL"] After deleting ::["JavaFX","HBase","JOGL"]

In Java Inheritance is a fundamental feature that allows a class to derive properties and behaviors from another class. In Java, not all classes can be subclassed. A final class is a special type of class that cannot be extended.  What is a Final Class in Java? In Java, a class is declared final using the final keyword. The final modifier for finalizing the implementations of classes, methods, and variables. When a class is marked as final, it means − It cannot be extended. All its methods remain unchanged in their ... Read More

The get method of the JSONArray class returns the element at a particular index. Using this method, you can get the elements of the JSONArray object and populate the array with them.Exampleimport java.util.Arrays; import org.json.JSONArray; public class JsonToArray {    public static void main(String args[]) throws Exception {       String [] myArray = {"JavaFX", "HBase", "JOGL", "WebGL"};       JSONArray jsArray = new JSONArray();       for (int i = 0; i < myArray.length; i++) {          jsArray.put(myArray[i]);      }      System.out.println(jsArray);      String[] array = new String[myArray.length];   ... Read More

Google provides a library named org.json.JSONArray and, following is the maven dependency to add library to your project. com.googlecode.json-simple json-simple 1.1 The JSONArray class of the org.json package provides put() method. Using this method, you can populate the JSONArray object with the contents of the elements.Exampleimport org.json.JSONArray; public class ArrayToJson { public static void main(String args[]) { String [] myArray = {"JavaFX", "HBase", "JOGL", "WebGL"}; JSONArray jsArray = new JSONArray(); ... Read More

The Arrays class of java package provides you a method named binarySearch() using this method you can perform a binary search on an array in Java.ExampleLive Demoimport java.util.Arrays; public class ArrayDemo {    public static void main(String[] args) {       int intArr[] = {30,20,5,12,55};       Arrays.sort(intArr);       System.out.println("The sorted int array is:");       for (int number : intArr) {          System.out.println("Number = " + number);       }       int searchVal = 12;       int retVal = Arrays.binarySearch(intArr,searchVal);       System.out.println("The index of element 12 is : " + retVal);    } }OutputThe sorted int array is: Number = 5 Number = 12 Number = 20 Number = 30 Number = 55 The index of element 12 is: 1

Following is the algorithm for heapsort (maxheap).Step 1 − Create a new node at the end of the heap.Step 2 − Assign new value to the node.Step 3 − Compare the value of this child node with its parent.Step 4 − If the value of parent is less than a child, then swap them.Step 5 − Repeat step 3 & 4 until Heap property holds.Exampleimport java.util.Arrays; import java.util.Scanner; public class Heapsort {    public static void heapSort(int[] myArray, int length) {       int temp;       int size = length-1;       for (int i ... Read More

To check to find whether a given array contains three consecutive dates:Convert the given array into a list of type LocalDate.Using the methods of the LocalDate class compare ith, i+1th and i+1th, i+2th elements of the list if equal the list contain 3 consecutive elements.ExampleLive Demoimport java.time.LocalDate; import java.time.Month; import java.util.ArrayList; import java.util.Collections; import java.util.Date; import java.util.List; public class ConsicutiveDate {    public static void main(String args[]) {       String[] dates = {"5/12/2017", "6/12/2017", "7/12/2017"};       List localDateList = new ArrayList();       for (int i = 0; i

You can convert an array list of strings to an array list of integers as:ExampleLive Demoimport java.util.ArrayList; import java.util.List; import java.util.stream.Collectors; public class LamdaExpressions {    public static void main(String args[]) {       ArrayList list = new ArrayList();       list.add("123");       list.add("223");       list.add("323");       list.add("334");       List listInteger =          list.stream().map(s -> Integer.parseInt(s)).collect(Collectors.toList());       System.out.println(listInteger);    } }Output[123, 223, 323, 334]

ExampleLive Demoimport java.util.Arrays; public class ArrayWithinAnArray{    public static void main(String args[]) {       int[] myArray1 = {23, 56, 78, 91};       int[] myArray2 = {123, 156, 178, 191};       int[] myArray3 = {223, 256, 278, 291};       int[] myArray4 = {323, 356, 378, 391};       int [][] arrayOfArrays = {myArray1, myArray2, myArray3, myArray4};       System.out.println(Arrays.deepToString(arrayOfArrays));    } }Output[[23, 56, 78, 91], [123, 156, 178, 191], [223, 256, 278, 291], [323, 356, 378, 391]]