import java.util.*

 public class ListExample {
    public static void main(String[] args) {
	 List list = new ArrayList();
	 list.add("one");
	 list.add("second");
	 list.add("3rd");
	 list.add(new Integer(4));
	 list.add(new Float(5.0F));
	 list.add("second"); // duplicate, is added
	 list.add(new Integer(4)); // duplicate, is added
	 System.out.println(list);
   }
 }

輸出結果：
[one, second, 3rd, 4, 5.0, second, 4]