用数组的格式模拟栈的入栈和出栈

package com.yuteng.stack;

import java.util.Scanner;

/**

• @version 1.0

• @author： 余腾

• @date： 2021-07-26 10:34
  */
  public class ArrayStackDemo {
  public static void main(String[] args) {
  ArrayStack stack = new ArrayStack(4);
  String key = "";
  boolean loop = true;//控制是否退出菜单
  Scanner scanner = new Scanner(System.in);
  while (loop) {
  System.out.println("show:表示显示栈");
  System.out.println("exit:表示退出程序");
  System.out.println("push:表示添加数据到栈");
  System.out.println("pop:表示从栈中取出数据");
  System.out.println("请输入你要进行的操作");
  key = scanner.next();
  switch (key) {
  case "show":
  stack.list();
  break;
  case "exit":
  scanner.close();
  loop = false;
  break;
  case "push":
  System.out.println("请输入你要输入的数据");
  int data = scanner.nextInt();
  stack.push(data);
  break;
  case "pop":
  try {
  int pop = stack.pop();
  System.out.println("出栈的数据是"+pop);
  }catch (Exception e){
  System.out.println(e.getMessage());
  }

               break;
           default:
               break;
  
       }
   }
   System.out.println("程序退出");
  

  }
  }

//定义一个ArrayStack表示栈
class ArrayStack {
private int maxSize;//栈的大小
private int[] stack;//数组，数组模拟栈，数据就放在该数组中
private int top = -1;//top表示栈顶

public ArrayStack(int maxSize) {
    this.maxSize = maxSize;
    stack = new int[this.maxSize];

}

//判断栈满
public boolean isFull() {
    return top == maxSize - 1;
}

//判断栈空
public boolean isEmpty() {
    return top == -1;
}

//入栈
public void push(int value) {
    //先判断是否满
    if (isFull()) {
        System.out.println("栈满");
        return;
    }
    top++;
    stack[top] = value;
}

public int pop() {
    //先判断是否栈空
    if (isEmpty()) {
        throw new RuntimeException("栈空不能返回数据");
    }
    return stack[top--];
}

//显示栈的情况[遍历栈]，遍历时，需要从栈顶开始显示数据
public void list() {
    if (isEmpty()) {
        System.out.println("栈空不能输出");
        return;
    }
    for (int i=top;i>=0;i--){
        System.out.println("stack["+i+"]="+stack[i]);
    }
}

}