我在循环中遇到麻烦总计也应该添加直到用户退出循环输入 N || n

Question

我似乎无法正确执行 do while 循环，我正在尝试制作一个接受订单的程序，询问是否还有订单，如果有，它将重新启动循环并跟踪总数。如果用户选择 N，则程序退出并完整打印总数。税率和邮政编码稍后会发挥作用我真的只需要一些循环部分的帮助。

//menue for berry shop

#include <iostream>
#include<cmath>
#include <iomanip>
using namespace std;

int main()
{

double a = 12.50, b = 19.99, c = 18.50, d = 35.00, e = 18.50,f = 35.00, totalprice;
const double TAX = 0.13;
char choice;
char answer;

do
{

    cout << "Fancy Fruits is pleased to provide Giant Strawberries for you today!";
    cout << "Your sales associate will be Phillip Ray " << endl;
    cout << ""<< endl;
    cout << "We deliver to these zipcodes"<< endl;
    cout << "----------------------------"<< endl;
            cout << "37918     37919" << endl;
            cout << "37920     37921" << endl;
            cout << "37922     37924" << endl;

    cout << "         Menu                                     Price "<< endl;
    cout << "         ----                                     ----- " <<endl;
    cout << "A:1 Dozen plain strawberries                      $" << a << endl;
    cout << "B:2 Dozen plain strawberries                      $" << b << endl;
    cout << "C:1 dozen choclate covered strawberries           $" << c << endl;
    cout << "D:2 Dozen choclate covered strawberries           $" << d << endl;
    cout << "E:1 Dozen dark choclate covered strawberries      $" << e << endl;
    cout << "F:2 Dozen dark choclate covered strawberries      $" << f << endl;
    cin >> choice;
    cout << "Are there any addtional orders? 'Y' or 'N'" << endl;
    cin >> answer;
    if (answer == 'y' || answer == 'Y')

    {   //Display Choice

        cout << "Your choice?" << endl;
    }


     if (choice == 'A' || choice == 'a')
     {

        cout << "A: One dozen plain strawberries" << a << endl;

     break;
    }


    if (choice == 'B' || choice == 'b')
    {

        cout << "B: Two dozen plain strawberries" << b << endl;
     break;
    }


  if (choice == 'C' || choice == 'c')
    {

        cout << "C:1 dozen choclate covered strawberries" << c << endl;
     break;
    }

 if (choice == 'D' || choice == 'd')
    {

        cout << "D: 2 dozen choclate covered strawberries " << d << endl;
     break;
    }


    if (choice == 'E' || choice == 'e')
    {

        cout << "E:1 dozen dark choclate covered strawberries " << e << endl;
     break;
    }
   

   if (choice == 'F' || choice == 'f')
            {

       cout << "F: 2 dozen dark choclate covered strawberries" << f << endl;
     break;
    }


       else if (answer == 'N' || answer == 'n')
    {
        cin >>  answer;

        cout << "The final bill for today is ";
        cout << totalprice <<endl;
    }

    else //Displaying error message
    {
        cout << "Invalid input";
}} 
while (answer != 'N' && answer != 'n');
{ (choice += totalprice);
}
return(0);  
}

Answer 1

您的代码有多个问题。我假设您想要这种行为：

显示菜单
问“你的选择？”
等待用户选择其中一个选项
询问用户是否还想订购其他东西
如果用户回答“是”，则转到第 2 步
如果用户回答“N”，则退出 while 循环并继续执行程序。

如果我的理解是正确的，第一个问题是你在打印出用户的选择后使用break。请记住 break 退出 do-while 循环。第二个问题是do-while循环的整个流程似乎是错误的。

这段代码产生的输出我认为是你想要的：

#include <iostream>
#include<cmath>
#include <iomanip>
using namespace std;

int main()
{
    double a = 12.50, b = 19.99, c = 18.50, d = 35.00, e = 18.50,f = 35.00, totalprice = 0;
    const double TAX = 0.13;
    char choice;
    char answer;

    cout << "Fancy Fruits is pleased to provide Giant Strawberries for you today!";
    cout << "Your sales associate will be Phillip Ray " << endl;
    cout << ""<< endl;
    cout << "We deliver to these zipcodes"<< endl;
    cout << "----------------------------"<< endl;
    cout << "37918     37919" << endl;
    cout << "37920     37921" << endl;
    cout << "37922     37924" << endl;
    cout << "         Menu                                     Price "<< endl;
    cout << "         ----                                     ----- " <<endl;
    cout << "A:1 Dozen plain strawberries                      $" << a << endl;
    cout << "B:2 Dozen plain strawberries                      $" << b << endl;
    cout << "C:1 dozen choclate covered strawberries           $" << c << endl;
    cout << "D:2 Dozen choclate covered strawberries           $" << d << endl;
    cout << "E:1 Dozen dark choclate covered strawberries      $" << e << endl;
    cout << "F:2 Dozen dark choclate covered strawberries      $" << f << endl;
    do
    {
        cin >> choice;

        switch(choice)
        {
        case 'A':
        case 'a':
            cout << "A: One dozen plain strawberries " << a << endl;
            totalprice += a;
            break;
        case 'B':
        case 'b':
            cout << "B: Two dozen plain strawberries " << b << endl;
            totalprice += b;
            break;
        case 'C':
        case 'c':
            cout << "C:1 dozen choclate covered strawberries " << c << endl;
            totalprice += c;
            break;
        case 'D':
        case 'd':
            cout << "D: 2 dozen choclate covered strawberries " << d << endl;
            totalprice += d;
            break;
        case 'E':
        case 'e':
            cout << "E:1 dozen dark choclate covered strawberries " << e << endl;
            totalprice += e;
            break;
        case 'F':
        case 'f':
            cout << "F: 2 dozen dark choclate covered strawberries" << f << endl;
            totalprice += f;
            break;
        default:
            cout << "Invalid input\n";
        }
        cout << "Are there any addtional orders? 'Y' or 'N'" << endl;
        cin >> answer;
        if (answer == 'y' || answer == 'Y')
        {   //Display Choice
            cout << "Your choice?" << endl;
        }
    } while (answer != 'N' && answer != 'n');
    cout << "The final bill for today is " << totalprice <<endl;
    return(0);
}

我使用了 switch-case 方案而不是 if 链，因为它看起来更好。我也推荐你：

处理缩进。当缩进一致时，您的代码更容易阅读和理解。
使用更有意义的变量名，而不是 a、b 之类的。
考虑使用更多 C++ 功能，尤其是 STL，因为您的程序基本上是一个使用 cin 和 cout 而不是 printf 和 scanf 的 C 程序。

也许查找代码风格指南并尝试遵循它是个好主意。

我在循环中遇到麻烦总计也应该添加直到用户退出循环输入 N || n

Im having trouble staying in the loop the total is also supposed to add till the user exits the loop with an input of N || n

c++

do-while