arraylist retainall 28collection 3c 3f 3e c 29 method in java

1import java.util.ArrayList;
2public class ArrayListRetainAllMethod
3{
4   public static void main(String[] args)
5   {
6      ArrayList<String> al1 = new ArrayList<String>();
7      al1.add("red");
8      al1.add("blue");
9      al1.add("green");
10      // create another ArrayList
11      ArrayList<String> al2 = new ArrayList<String>();
12      al2.add("red");
13      al2.add("green");
14      al2.add("indigo");
15      al2.add("yellow");
16      // printing ArrayList before using retainAll() method
17      System.out.println("ArrayList 1: " + al1);
18      System.out.println("ArrayList 2: " + al2);
19      // applying retainAll() method to al2 passing al1 as parameter
20      al2.retainAll(al1);
21      System.out.println("After Applying retainAll() method to al2: ");
22      System.out.println("ArrayList 1: " + al1);
23      System.out.println("ArrayList 2: " + al2);
24   }
25}