Java Collection How to - Retain Another Collection

• Back to List  ↑

Question

We would like to know how to retain Another Collection.

Answer

import java.util.ArrayList;
import java.util.List;
/*  w  w  w .  j  a v a  2 s  .co  m*/
public class MainClass {
  public static void main(String args[]) throws Exception {

    List list = new ArrayList();
    list.add("A");
    list.add("A");
    list.add("B");
    list.add("B");
    list.add("C");
    list.add("C");
    list.add("D");

    List list2 = new ArrayList();
    list2.add("A");
    list2.add("B");
    list2.add("C");
    list.removeAll(list2);

    System.out.println(list);
  }
}

The code above generates the following result.

• Back to List  ↑