java data structures - stack underlying implementation: array implemented push, pop, empty stack test code is determined

package com.stack;

/**
 * @auther 付强
 * @date 2020/2/13 - 13:08
 */
public class TestMystack {
    public static void main(String[] args) {
        //先创建一个栈
        Mystack mystack = new Mystack();
        //压入数据
        mystack.push(9);
        mystack.push(8);
        mystack.push(7);
        mystack.push(6);
        mystack.push(5);
        System.out.println(mystack.pick());
        System.out.println(mystack.pop());
        System.out.println(mystack.pop());
        System.out.println(mystack.pop());
        System.out.println(mystack.pick());
        System.out.println(mystack.isEmpty());
    }
}