Using Sets : Set « Utility Classes « SCJP

1. SCJP
2. Utility Classes
3. Set

import java.util.HashSet;
import java.util.Set;

public class MainClass{
  public static void main(String[] args) {
    boolean[] ba = new boolean[5];
    // insert code here
    Set s = new HashSet();
    ba[0] = s.add("a");
    ba[1] = s.add(new Integer(42));
    ba[2] = s.add("b");
    ba[3] = s.add("a");
    ba[4] = s.add(new Object());
    
    for (int x = 0; x < ba.length; x++){
      System.out.print(ba[x] + " ");
    }
    
    System.out.println("\n");
    for (Object o : s){
      System.out.print(o + " ");
    }    
  }
}

true true true false true 

b a 42 java.lang.Object@3e25a5