Collection: containsAll(Collection c) Returns true if this collection contains every element of c : Collection « Utility Classes « SCJP

1. SCJP
2. Utility Classes
3. Collection

import java.util.ArrayList;
import java.util.Collection;

public class MainClass {
  public static void main(String[] argv) {
    Collection c = new ArrayList();
    c.add("1");

    Collection c2 = new ArrayList();
    c2.add("1");

    System.out.println(c.containsAll(c));
  }
}

true