How to achieve abstraction ?
Ans :- we can achieve abstraction by using abstract classes and Interfaces. Abstraction in java can be achieved in two ways:
Category: Java Trending Questions
What is the difference between JDK,JRE & JVM ?
Ans :- JDK :- JDK stands for “Java Development Kit” and which is the collection of the following : – 1. JavaCompiler 2.JVM 3.Java Library JRE :- JRE stands for “Java Runtime environment” which is the collection of JVM and …
Q. Write a simple program to swap the numbers.
Like if we have – a=20; b=30; I want a=30; and b=20; SOLUTION :- package p1; public class SwapNumbers { }
How to sort elements in Ascending and Descending Order?
SOLUTION :- package mv; import java.util.ArrayList;import java.util.Collections;import java.util.List; public class AscendingAndDescendingIntegers { }
What is flatMap() ? Write code for flatMap.
Ans:- flatMap() :- flatMap() transform each element and flattern the resulting collection into a single combined collection. Example of flatMap():- package v1;import java.util.ArrayList; import java.util.Arrays; import java.util.List;import java.util.stream.Collectors; public class FlatMapExample {public static void main(String[] args) { List<List<Integer>> list=new ArrayList<>(); …
How to find Count of element using stream?
Solution :- we will use Map to find Count of element using stream package p2; import java.util.Arrays; import java.util.List; import java.util.Map; import java.util.stream.Collectors; public class CountOfElement { public static void main(String[] args) { List<Integer> list=Arrays.asList(1,1,2,3,3,5,5,7,8,9,9); Map<Integer,Long> map=list.stream().collect(Collectors.groupingBy(i->i,Collectors.counting())); System.out.println(map); map=map.entrySet().stream().filter(e->e.getValue()>1).collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)); …
How to find Two digit element in this Array int[] abc= {2,1,3,44,52,23}; using For-Loop.
SOLUTION :- package p3; public class ArrayTwoDigitCount { public static void main(String[] args) { int[] abc= {2,1,3,44,52,23}; for(int i: abc) { if(i>=10 && i<=99) { System.out.println(“Two-digit-elements :”+i); } } } } ****************************************************************
What is the Difference between Collection and Collections ?
Ans :- the main difference between Collection and Collections :- 1.Collection<E> 2.Collections 1.Collection<E> => Collection <E> is an interface from java.util package and which is the root of Java Collection<E> Framework. 2.Collections : => “Collections” is a Class from java.util …
What is the Difference between Collection and Collections ? Read more »
Difference between Vector and Arraylist in Java
In Java ArrayList and Vector classes both are implements List Interface, and both are using resizable and growable Array for internal data structure. Differences with respect to : Methods: Thread Safety: Performance: Legacy: Increment Size:
How to remove duplicate element by using Java 8 feature?
Solution :- import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; public class DuplicateElement { public static void main(String[] args) { List<Integer> list=Arrays.asList(1,1,2,3,3,3,5); list=list.stream().distinct().collect(Collectors.toList()); System.out.println(list); } } *****************************************************