import java.util.Date;
import java.util.Stack;

public class TestStack{
    public static void main(String[] args) {
        Stack s = new Stack();
        s.push("hello");
        s.push(new Date());
        s.push(400);  //自动封装,等价于s.push(new Integer(400));
        s.push(3.14);
        
        System.out.println("弹栈前:size=" + s.size());
        System.out.println(s.pop());
        System.out.println("弹栈后:size=" + s.size());
        System.out.println(s.peek());
        System.out.println("peek操作后:size=" + s.size());
        while(!s.isEmpty())
            System.out.println(s.pop());
    }
}