Find the common elements in 2 list(arraylist)
import java.util.*;
class ASC
{
public static void main(String args[])
{
ArrayList<Integer> a=new ArrayList<>();
a.add(1);
a.add(2);
a.add(3);// 1 2 3
ArrayList<Integer> b=new ArrayList<>();
b.add(4);
b.add(2);
b.add(5);//4 2 5
a.retainAll(b);//retainall will keep only the common values
System.out.println(a);}}