public class HashSetDemo
1: //HashSetDemo.java
2: //Illustrates the following HashSet methods:
3: //add()
4: //remove()
5: //contains()
6: //toArray()
7:
8: import java.util.HashSet;
9:
10: public class HashSetDemo
11: {
12: public static void main(String[] args)
13: {
14: HashSet<Integer> intSet = new HashSet<Integer>();
15:
16: intSet.add(2);
17: intSet.add(7);
18: intSet.add(7); // Ignored since 7 is already in the set
19: intSet.add(3);
20: printSet(intSet);
21:
22: intSet.remove(3);
23: printSet(intSet);
24:
25: System.out.println("Set contains 2: " +
26: intSet.contains(2));
27: System.out.println("Set contains 3: " +
28: intSet.contains(3));
29: }
30:
31: public static void printSet(HashSet<Integer> intSet)
32: {
33: System.out.println("The set contains:");
34: for (Object obj : intSet.toArray())
35: {
36: Integer num = (Integer) obj;
37: System.out.println(num.intValue());
38: }
39: }
40: }