Java订货系统中如何计算总价？
我只是一名大学一年级的学生，我的项目是创建一个订购系统，但我在定价上卡住了，因为我不能正确地计算总价。当程序循环时，它计算的价格是错误的。A1和A2是我唯一的选择，因为这仍然是一个未完成的项目Java订货系统中如何计算总价？,java,Java,我只是一名大学一年级的学生，我的项目是创建一个订购系统，但我在定价上卡住了，因为我不能正确地计算总价。当程序循环时，它计算的价格是错误的。A1和A2是我唯一的选择，因为这仍然是一个未完成的项目 import java.io.*; public class Ordering_System { public static void main(String []args) throws Exception { BufferedReader br=new Buffe
import java.io.*;
public class Ordering_System
{
public static void main(String []args) throws Exception
{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
String order,again;
int quantity,price1=0,price2=0,loop1=0,quantity1,quantity2=0;
System.out.println(" ");
System.out.println("Welcome to MgRonalds, What do you want to order?");
System.out.println(" ");
System.out.println("*******************************************************************");
System.out.println("* Code Meal ''MENU'' Price *");
System.out.println("* *");
System.out.println("* (A1) MgBurger P30.00 *");
System.out.println("* (A2) Big Mac P139.00 *");
System.out.println("* (B1) Cheese Burger P35.00 *");
System.out.println("* (B2) Chicken Burger P50.00 *");
System.out.println("* (C1) MgNuggets P65.00 *");
System.out.println("* (C2) MgChicken P79.00 *");
System.out.println("* (D1) MgSpagetti P60.00 *");
System.out.println("* (D2) MgFries P40.00 *");
System.out.println("* (E1) Coke P10.00 *");
System.out.println("* (E2) Sprite P10.00 *");
System.out.println("* (E3) Royal P10.00 *");
System.out.println("* (F1) Sundae P25.00 *");
System.out.println("* (F2) MgFloat P25.00 *");
System.out.println("* *");
System.out.println("*******************************************************************");
do{
System.out.println("");
System.out.print("Enter Code Order : ");
order=br.readLine();
if (order.equalsIgnoreCase("A1")) {
price1=30;
System.out.println("Order Description : MgBurger ");
} else if (order.equalsIgnoreCase("A2")) {
price1=139;
System.out.println("Order Description : Big Mac ");
}
System.out.print("Enter Quantity : ");
quantity1= Integer.parseInt(br.readLine());
quantity2=quantity1+quantity2;
price2=price1*quantity2;
System.out.print("Another Order? (Y/N) : ");
again=br.readLine();
if (again.equalsIgnoreCase("y"))
loop1=loop1+1;
else loop1=loop1-100;
} while (loop1==1);
System.out.println(" ");
System.out.println("Total Price : "+price2);
}
}
Enter Code Order : a1
Order Description : MgBurger
Enter Quantity : 2
Another Order? (Y/N) : y
Enter Code Order : a2
Order Description : Big Mac
Enter Quantity : 2
Another Order? (Y/N) : n
Total Price : 556
答案应该是338而不是556让我们逻辑地解决这个问题： 在第一个循环中： 输入代码顺序：a1 现在，
price1=30price1=30quantity1=2quantity2=2price2=60发现错误了吗
quantity2total=0
System.out.print("Enter Quantity : ");
quantity1 = Integer.parseInt(br.readLine());
// quantity2=quantity1+quantity2;
// price2=price1*quantity2;
total += price1 * quantity1;
...
System.out.println(" ");
System.out.println("Total Price : " + total);
您可以将代码简化如下。也可以考虑使用浮动值来代替价格INT/P>
public static void main(String[] args) throws Exception {
System.out.println(" ");
// Display the Menu
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String order, again;
int quantity = 0;
int total = 0;
while (true) {
System.out.println("");
System.out.print("Enter Code Order : ");
order = br.readLine();
System.out.print("Enter Quantity : ");
quantity = Integer.parseInt(br.readLine());
total += getPrice(order) * quantity;
System.out.print("Another Order? (Y/N) : ");
again = br.readLine();
if (again.equalsIgnoreCase("N")) {
break;
}
}
System.out.println(" ");
System.out.println("Total Price : " + total);
}
private static int getPrice(String order) {
int price = 0;
// using switch-case would be more appropriate
if (order.equalsIgnoreCase("A1")) {
price = 30;
System.out.println("Order Description : MgBurger ");
} else if (order.equalsIgnoreCase("A2")) {
price = 139;
System.out.println("Order Description : Big Mac ");
}
return price;
}
我建议您在调试器中单步执行代码，并在代码执行期间观察值。我打赌你会很快发现你在哪里根据错误的值计算东西：）而且，如果你给你的变量提供更具描述性的名称，比如totalPrice
和priceForCurrentItem
等，也会有所帮助，当您在错误的位置使用变量时，这将更加清楚。我从来不知道McDonalds
有一个名为MgRonalds
的新特许经营权：谢谢你！！你真的帮了我这个忙。从昨天起这就是我的问题。。
quantity1 = 2;
quantity2 = quantity1 + quantity2 = 2 + 2 = 4;
price2 = 139 * 4 = 556;
System.out.print("Enter Quantity : ");
quantity1 = Integer.parseInt(br.readLine());
// quantity2=quantity1+quantity2;
// price2=price1*quantity2;
total += price1 * quantity1;
...
System.out.println(" ");
System.out.println("Total Price : " + total);
public static void main(String[] args) throws Exception {
System.out.println(" ");
// Display the Menu
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String order, again;
int quantity = 0;
int total = 0;
while (true) {
System.out.println("");
System.out.print("Enter Code Order : ");
order = br.readLine();
System.out.print("Enter Quantity : ");
quantity = Integer.parseInt(br.readLine());
total += getPrice(order) * quantity;
System.out.print("Another Order? (Y/N) : ");
again = br.readLine();
if (again.equalsIgnoreCase("N")) {
break;
}
}
System.out.println(" ");
System.out.println("Total Price : " + total);
}
private static int getPrice(String order) {
int price = 0;
// using switch-case would be more appropriate
if (order.equalsIgnoreCase("A1")) {
price = 30;
System.out.println("Order Description : MgBurger ");
} else if (order.equalsIgnoreCase("A2")) {
price = 139;
System.out.println("Order Description : Big Mac ");
}
return price;
}