15章 上机4

import java.util.Scanner;public class Demo8 {String[] goods = new String[]{"电风扇","洗衣机","电视机","冰箱","空调机"};double[] price = new double[]{124.23,4500,8800.90,5000.88,4456,12000.46};public boolean login(){boolean flag=false;Scanner input = new Scanner(System.in);System.out.print("请输入用户名:");String name = input.next();System.out.print("请输入密码:");String mima = input.next();if(name.equals("tom")&&mima.equals("123")){System.out.println("登陆成功");flag=true;}else{System.out.println("用户名密码输入错误");}return flag;}public StringBuffer change(double d){StringBuffer str=new StringBuffer(String.valueOf(d));for(int i=str.indexOf(".")-3;i>0;i=i-3){str.insert(i,',' );}return str;}public void show(){System.out.println("****************欢迎进入商品批发城**************");System.out.println("\t\t编号\t商品\t价格\t\t");for(int i=0;i<goods.length;i++){System.out.print("\t\t"+(i+1)+"\t");System.out.print(goods[i]+"\t");System.out.print(change(price[i]));System.out.println(" ");}}

public static void main(String[] args) {Demo8 s = new Demo8(); String name; double money = 0; double num;s.login();s.show();Scanner input = new Scanner(System.in);System.out.print("请输入您批发的商品编号:");int hao = input.nextInt();switch(hao){case 1:name="电风扇";money=124.23;break;case 2:name="洗衣机";money=4500.0;break;case 3:name="电视机";money=8800.9;break;case 4:name="冰箱";money=5000.88;break;case 5:name="空调";money=4456.0;break;}System.out.print("请输入批发的数量:");int shu = input.nextInt();num=money*shu;System.out.println("您需要付款"+s.change(num));}}