零钱通练习

零钱通练习

要求

思路 -化繁为简

• 先完成显示菜单，并可以选择
• 完成零钱通明细.
• 完成收益入账
• 消费
• 退出

代码1：用来完成各个功能

package com.gqz.smallchange.OOP;


import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;

/**
 * 该类用来完成各个功能，面向对象
 * 将各个功能对应一个方法
 */
public class SmallChangeOOP {
    //属性
    boolean loop = true;
    Scanner scanner = new Scanner(System.in);
    String key = "";

    String details = "--------收益明细--------";

    double money = 0;
    double balance = 0;
    Date date = null;
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");//用于日期格式化
    //消费说明
    String note = "";


    //先完成显示菜单
    public void mainMenu() {
        do {
            System.out.println("=====选择零钱通菜单=====");
            System.out.println("\t\t\t1 零钱通明细");
            System.out.println("\t\t\t2 收益入账");
            System.out.println("\t\t\t3 消费");
            System.out.println("\t\t\t4 退     出");

            System.out.print("请选择（1-4）：");
            key = scanner.next();

            //使用switch控制分支
            switch (key) {
                case "1":
                    this.detail();
                    break;
                case "2":
                    this.income();
                    break;
                case "3":
                    this.pay();
                    break;
                case "4":
                    this.exit();
                    break;
                default:
                    System.out.println("菜单选择有误");
            }
        } while (loop);
    }

    //明细
    public void detail() {
        System.out.println(details);
    }

    //收入
    public void income() {
        System.out.print("输入收入金额:");
        money = scanner.nextDouble();
        //校验 找出不正确的金额
        if (money <= 0) {
            System.out.println("收益入账金额需要大于0");
            return;//退出方法，不再执行后面代码
        }
        date = new Date();//当前日期
        balance += money;
        details += "\n收益入账\t" + money + "\t" + sdf.format(date) + "\t余额\t" + balance;
    }

    //消费
    public void pay() {
        System.out.print("消费金额:");
        money = scanner.nextDouble();
        //校验
        if (money <= 0 || money > balance) {
            System.out.println("消费金额应该在0-" + balance);
            return;
        }
        System.out.print("消费说明:");
        note = scanner.next();
        balance -= money;
        date = new Date();
        details += "\n" + note + "\t-" + money + "\t" + sdf.format(date) + "\t余额\t" + balance;
    }

    public void exit() {
        String choice = "";
        while (true) {
            System.out.println("你确定要退出么（输入y/n）");
            choice = scanner.next();
            if ("y".equals(choice) || "n".equals(choice)) {
                break;
            }
        }
        //当用户退出while后
        if (choice.equals("y")) {
            loop = false;
        }
    }
}

代码2：调用

package com.gqz.smallchange.OOP;

public class SmallChangeOOPapp {
    public static void main(String[] args) {
        new SmallChangeOOP().mainMenu();
    }
}