问题描述
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。税率和邮政编码将在后面起作用，我真的只需要循环部分的一些帮助。
//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);
}
解决方法
您的代码有多个问题。我假设您想要这种行为：
- 显示菜单
- 询问“您的选择？”
- 等待用户选择其中一个选项
- 询问用户是否想订购其他东西
- 如果用户回答“是”，请转到第 2 步
- 如果用户回答“N”，则退出 while 循环并继续执行程序。
如果我的理解是对的，第一个问题是你在打印出用户的选择后使用了break。请记住 break 退出 do-while 循环。第二个问题是do-while循环的整个流程看起来是错误的。
这段代码产生了我认为是你想要的输出：
#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。当您使用一致的缩进时，您的代码更易于阅读和理解。
- 使用更有意义的变量名称，而不是
a、b和排序。 - 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 C 程序，它使用
cin和cout而不是printf和scanf。立>
也许查找代码风格指南并尝试遵循它是个好主意。