What is the difference between List and Set ?

-

Q. What is the difference between List and Set. 


Ans:-

s.No

List

Set

1.

List allow duplicates

Set does’t allow duplicates

2.

The List is an ordered collection which maintains the insertion order.

Whereas set is an unordered collection which does not preserve the insertion order.

3.

The List interface contains a single legacy class which is vector class

Where as set interface does not have any legacy class

4.

The List Interface can allow n number of null values

5.set Interface only allows a Single null value

Comments

Post a Comment

Popular posts from this blog

How to create React project using command prompt?

-
Image
  How to create React project using command prompt? Ans :- firstly you have to install node js and npm in your system after after that follow these steps:- Step 1:- Open command prompt and for create project write  npx create-next-app Step 2:- Now it will say to write your Project name. Step 3 :- Now write your project name as per your choice. Step 4 :- Now it will ask what is your needs to create a project   Step 5 :- Now you can see dependencies are Installed as shown in below image Step 6 :- Now use this command for change the directory Step 7 :- Now you can see below directory is changed Step 8 :- Now for open the project in Vs code use this command  code . Step 9 :- Now you can see your project is directly opened in Visual Studio Code
Read more

How to achieve abstraction?

-
 Q. How to achieve abstraction ? Ans :- we can achieve abstraction by using abstract classes and Interfaces. Abstraction in java can be achieved in two ways: Using abstract classes:- Abstract classes achieve partial abstraction as concrete methods can also be defined in them. Using Interfaces :- Interfaces achieve complete abstraction as only abstract methods can be defined in them.
Read more

Interview Question? How to find square of each element in this Array {2,4,5,6,8} using map ?

-
 Q. How to find square of each element in this Array {2,4,5,6,8} Output : [4, 16, 25, 36, 64] Solution :- package p3; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; public class MapExample { public static void main(String[] args) { Integer[] abc={2,4,5,6,8}; List<Integer> list=Arrays.asList(abc); List<Integer> squareEle=list.stream().map(i->i*i).collect(Collectors.toList()); System.out.println(squareEle); for(Integer i:squareEle) { System.out.println(i); }   } } ******************************************************************** O/P:-  Output : [4, 16, 25, 36, 64]
Read more