Why Interface in Java ?

Ans:

1. Support the functionality of multiple inheritance.

2. Achieve fully abstraction.

3. Achieve loose coupling, which is the biggest advantage of interface.

How to sort ArrayList in JAVA.

To sort values in ArrayList, we use Collections class, and invoke sort() method. consider this example:

package java8s;

 

import java.util.*;

 

public class SortCollectionDemo {

 

public static void main(String[] args)

{

 

    List li = new ArrayList();

 

    li.add("Santosh");

    li.add("Akshay");

    li.add("Tapuuu");

    li.add("Millan);

    li.add("Rakesh");

 

    Collections.sort(li);

 

for(String temp: li)

{

System.out.println("Countries : "+temp);

}

}

}

Output:

Akshay

Millan

Rakesh

Santosh

Tapuuu