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]]

If a class is declared final, you cannot inherit it. If you try it gives you a compile-time error as − Example final class Super { private int data = 30; } public class Sub extends Sub { public static void main(String args[]){ } } Output Exception in thread "main" java.lang.Error: Unresolved compilation problem: at Sub.main(Sub.java:7)

No, a child class can’t inherit private members of the parent class, it can inherit only protected, default, and public members of it. If you try it gives you a compile time error as: − Example class Super{ private int data = 30; public void display(){ System.out.println("Hello this is the method of the super class"); } } public class Sub extends Super{ public void greet(){ System.out.println("Hello this is the method of the sub class"); ... Read More

Java supports inheritance, an OOPs concept where one class acquires the members (methods and fields) of another.You can inherit the members of one class from another, use the extends keyword as:class A extends B{}The class which inherits the properties of other is known as child class (derived class, sub class) and the class whose properties are inherited is known as parent class (base class, superclass class).Following is an example which demonstrates inheritance. Here, we have two classes namely Sample and MyClass. Where Sample is the parent class and the class named MyClass is the child class.ExampleLive Democlass Sample{    public ... Read More

In Java, static members are those which belongs to the class and you can access these members without instantiating the class. The static keyword can be used with methods, fields, classes (inner/nested), blocks. Static Methods − You can create a static method by using the keyword static. Static methods can access only static fields, methods. To access static methods there is no need to instantiate the class, you can do it just using the class name as − Example Live Demo public class MyClass { public static void sample(){ ... Read More

Following is the syntax to declare a method in Java. Syntax modifier return_type method_name(parameters_list){ //method body } Where, modifier − It defines the access type of the method and it is optional to use. return_type − Method may return a value. method_name − This is the method name. The method signature consists of the method name and the parameter list. parameters_list − The list of parameters, it is the type, order, and a number of parameters of a method. These are optional, method may contain zero parameters. method body − The method body defines ... Read More