十四章上机练习4

import java.util.*;
public class Goods {
String[] goods=new String[]{"电风扇","洗衣机","电视机","冰箱","空调机"};
double[] price=new double[]{124.23,4500,8800.90,5000.88,4456,1200.46};

double total;
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 pwd=input.next();
if(name.equals("Tom")&&pwd.equals("123")){
System.out.println("登录成功");
flag=true;
}else{
System.out.println("请重新登录");

}
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(){
Scanner input=new Scanner(System.in);
System.out.println("*********欢迎进入商品批发城*********");
System.out.println("\t编号\t商品\t价格");
for(int i=0;i<goods.length;i++){
System.out.println("\t"+(i+1)+"\t"+goods[i]+"\t"+change(price[i]));
}
System.out.println("************************************");
System.out.print("请输入您批发的商品编号: ");
int choice=input.nextInt();
System.out.print("请输入批发数量: ");
int number=input.nextInt();
switch(choice){
case 1:
total=price[0]*number;
break;
case 2:
total=price[1]*number;
break;
case 3:
total=price[2]*number;
break;
case 4:
total=price[3]*number;
break;
case 5:
total=price[4]*number;
break;
}
System.out.println("您需要付款:"+change(total));
}

public static void main(String[] args) {
Goods g=new Goods();

g.login();
g.show();
}
}