找错（菜鸟问题）

[阿杰不爱]

如题

package university.deparment.biology.students.book;

import java.util.Scanner;

public class Consumption {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("请输入金额");
boolean flag = true;
double money = input.nextDouble();
System.out.println("是否参加优惠换购活动");
System.out.println("1：满五十元加两元参加换购百事可乐一瓶");
System.out.println("2：满一百元加三元换500ml可乐一瓶");
System.out.println("3：满一百元加十元换购一百斤面粉");
System.out.println("4：满一百元加十元换购一个苏泊尔锅");
System.out.println("5：满200元加二十元可换购欧莱雅爽肤水一瓶");
System.out.println("0：不换购");
String result="";
System.out.println("请选择：");
int i= input.nextInt();
if (i<50) {
flag = false;
}else{
switch (i) {
case 1:
result = "百事可乐一瓶";
money+=2 ;
break;
case 2:
if (i<100) {
flag = false;
}
result="500ml可乐一瓶";
money+=3;
break;
case 3:
if (i<100) {
flag = false;
}
result= "5公斤面粉";
money+=10;
break;
case 4:
if (i<200) {
flag = false;
}
result="一个苏泊尔炒菜锅";
money+=10;
break;
case 5:
if (i<200) {
flag = false;
}
result="欧莱雅爽肤水一瓶";
money+=20;
break;

default:
flag = false;
break;
}
}
System.out.println("本次消费金额："+money);
if (flag) {
System.out.println("成功换购"+result);
}else{
System.out.println("换购失败");
}
}
}
运行结果总是：换购失败

[abc41106]

1.你判断的地方写错了，应该用 if(money < 100)，不应该用i 2.if判断里面最好写break,不然它还会走result= "5公斤面粉";money+=10; 虽然你这个不会错，但有隐患。

[安特矮油]

你的代码没格式不好看，写了一个，你看看吧

package com.study.test;

import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
import java.util.Map.Entry;

public class Test {

	private static Map<Integer, Domain> map = new LinkedHashMap<Integer, Domain>();
	
	static{
		map.put(1, new Domain(2, 50, "满50元，加2元参加换购百事可乐1瓶", "百事可乐1瓶"));
		map.put(2, new Domain(3, 100, "满100元，加3元换500ml可乐1瓶", "500ml可乐1瓶"));
		map.put(3, new Domain(10, 100, "满100元，加10元换购5公斤面粉", "5公斤面粉"));
		map.put(4, new Domain(10, 200, "满200元，加10元换购1个苏泊尔锅", "苏泊尔锅1个"));
		map.put(5, new Domain(20, 200, "满200元，加20元可换购欧莱雅爽肤水1瓶", "欧莱雅爽肤水1瓶"));
		map.put(0, new Domain(0, 0, "不换购", ""));
	}
	
	public static void main(String[] args){
		double money = 0.0;
		while(true){
			Scanner input = new Scanner(System.in);
			System.out.println("请输入金额");
			try {
				money = input.nextDouble();
				break;
			} catch (Exception e) {
				System.out.println("输入的金额有误，请重新输入！！");
			}
		}
		Set<Entry<Integer, Domain>> entrys = map.entrySet();
		Iterator<Entry<Integer, Domain>> iter = entrys.iterator();
		while(iter.hasNext()){
			Entry<Integer, Domain> entry = iter.next();
			System.out.println(entry.getKey() + ": " + entry.getValue());
		}
		System.out.println("请选择：");
		Domain domain = null;
		while(true){
			try {
				Scanner input = new Scanner(System.in);
				int type = input.nextInt();
				domain = map.get(type);
				if(domain != null){
					break;
				}else{
					System.out.println("选择的方式不存在，请重新输入！！");
				}
			} catch (Exception e) {
				System.out.println("输入的兑换方式有误，请重新输入！！");
			}
		}
		double addmoney = domain.getPrice();
		System.out.println(money + addmoney);
		if(addmoney > 0){
			System.out.println("成功换购：" + domain.getValue());
		}else{
			System.out.println("没参加换购活动。");
		}
	}
	
	
	
}

class Domain{
	private double price;
	private double over;
	private String name;
	private String value;
	
	public Domain(double price, double over, String name, String value){
		this.price = price;
		this.over = over;
		this.name = name;
		this.value = value;
	}
	public double getPrice() {
		return price;
	}
	public void setPrice(double price) {
		this.price = price;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	public double getOver() {
		return over;
	}
	public void setOver(double over) {
		this.over = over;
	}
	
	public String getValue() {
		return value;
	}
	public void setValue(String value) {
		this.value = value;
	}
	public String toString(){
		return name;
	}
	
}

[阿杰不爱]

谢谢一楼二楼。 二楼大哥太专业我看不懂！我刚学到循环！