Question

所以我有这个代码，但我遗漏了一些东西，我似乎无法得到它。这一点是提示用户进行选择。他们挑选他们想要订购的食物，并告诉他们添加了。当用户点击0时，程序结束时说出他们选择的所有项目的总数。出于某种原因，当我到达终点时，它只是说明添加的最后一项的总和。关于如何解决这个问题以便总计加起来的任何想法？

#include<stdio.h>

#define SALES_TAX .06

int selection;
double total;
double amount;
int i;

double getPrice(int selection);


void printOptionName(int selection);


void printMenu();


double getPrice(int selection){

    if (selection == 1){
        amount = 5.99;
    } else if (selection == 2){
        amount = 6.99;
    } else if (selection == 3){
        amount = 7.99;
    } else if (selection == 4){
        amount = 10.50;
    } else if (selection == 5){
        amount = 3.50;
    }

}

void printOptionName(int selection){

    if (selection == 0){
        printf("\nYour total is: ");
    } else if (selection == 1){
        printf("\nAdded a Small Pizza\n\n");
    } else if (selection == 2){
        printf("\nAdded a Medium Pizza\n\n");
    } else if (selection == 3){
        printf("\nAdded a Large Pizza\n\n");
    } else if (selection == 4){
        printf("\nAdded an order of Wings\n\n");
    } else if (selection == 5){
        printf("\nAdded a Drink\n\n");
    } else
        printf("Not a valid selection. Please select one of the following options: \n");
}


void printMenu(){

printf("0. (Complete Order)\n");
printf("1. Small Pizza ****** 5.99\n");
printf("2. Medium Pizza ****** 6.99\n");
printf("3. Large Pizza ****** 7.99\n");
printf("4. Wings ****** 10.50\n");
printf("5. Drink ****** 3.50\n");
printf("Enter the Number of your selection: \n");

}

int main(){

    printMenu();
    scanf("%d", &selection);
    printOptionName(selection);
    getPrice(selection);

    while (selection != 0){
        printMenu();
        scanf("%d", &selection);
        printOptionName(selection);
        getPrice(selection);
    }

    for (i = 0; i <= selection; i++){
        total = total + amount;
    }

    printf("%lf\n", total);

    return 0;
}

Answer 1

全局变量不是一个好方法。请注意，您未在selection中使用printmenu()，例如;您可能希望将必要的数据作为参数传递给函数。此外，您似乎在通过值传递的函数中通过引用传递。请注意，如果您的程序转到else中的printOptionName()语句，或getPrice()中的选项仍为零，则您的程序不会停止...

C编程帮助 - 一起添加值

1 个答案: