Java用数组模拟栈，栈中可以存储任意引用类型的对象

由于可以存储任意引用类型的对象，所以数组定义为Object

public class ArrayTest06 {
    public static void main(String[] args) {
        String s1="1234";
        MyStack ms= new MyStack(new Object[4],-1);//初始化栈，可以存放四个对象
        Object o=new Object();                      
        ms.PopMyStack(o);                                  //弹栈，栈空    打印：栈中无元素
        ms.PushMyStack(s1);                                //第一次进栈
        ms.PushMyStack("43321");                           //第二次进栈
        int i=ms.PushMyStack("Hello");                     //第三次进栈
        ms.PushMyStack(new Teacher());                     //第四次进栈
        ms.PushMyStack(new Student());                     //第五次进栈失败 打印：栈满了！
        ms.PopMyStack(o);                                  //弹栈  
        System.out.println(i);                             //              打印：1
        System.out.println(ms.getIndex());          //现在有三个元素        打印：2
        System.out.println(ms.getElements()[ms.getIndex()]);      //打印栈顶元素：  Hello
        System.out.println(o);                        //默认调用toString()  打印：对象的地址
    }
}
class MyStack{
    private Object[] elements;
    private int index;

    public MyStack() {
        this.elements=new Object[10];
        this.index=-1;
    }

    public MyStack(Object[] elements, int index) {
        this.elements = elements;
        this.index = index;
    }

    public Object[] getElements() {
        return elements;
    }

    public void setElements(Object[] elements) {
        this.elements = elements;
    }

    public int getIndex() {
        return index;
    }

    public void setIndex(int index) {
        this.index = index;
    }

    public int PushMyStack(Object o){
        if(this.getElements().length==this.index+1) {
            System.out.println("栈满了！");
            return 0;
        }
        this.setIndex(this.getIndex()+1);
        this.getElements()[this.getIndex()]=o;
        return 1;
    }
    public int PopMyStack(Object o){
        if(this.getIndex()==-1){
            System.out.println("栈中无元素");
            return 0;

        }
        o=this.getElements()[this.getIndex()];
        this.setIndex(this.getIndex()-1);
        return 1;
    }

}
class Student{

}
class Teacher{

}