C++ 开关格式中的循环不允许我显示菜单选项或接受输入？

Question

我需要为一门课程编写一个贷款程序，到目前为止我有这段代码：

    /*
    Project: Course Project - Loan Calculator
    Program Description: To calculate customer's loan
 information including interest rate, monthly
 payment and number of months payments will be
 required for.
 Developer: ___________
 Last Update Date: June 1st, 2020
 */

#include <iostream>
#include <string>


//variables listed here
double loanAmt = 0, intRate = 0, loanLength = 0;
std::string CustName[0];
int choice; //menu choice identifier


using namespace std;
int main()
{
    //Welcome User
    cout << "Thank you for using our calculator." << endl;
    cout << endl;
    cout << "Please enter the number of your preferred calculator and press 'Enter': " << endl;
    cout << endl;
    cin >> choice;

    {
        while (choice !=4);
        switch (choice)
        {
            case 1:
                cout << "Monthly Payment Calculator:";
                cout << endl;
                break;
            case 2:
                cout << "Interest Rate Calculator:";
                cout << endl;
                break;
            case 3:
                cout << "Payment Term (In Months):";
                cout << endl;
            case 4:
                cout << "Exit Calculator:";

            default: //all other choices
                cout << "Please Select A Valid Option.";
                break;

        }
    }
}

我试过移动 cin << 选择；到许多不同的地方，包括为开关编写的 while 循环内部，但我似乎只能让它显示菜单提示，而不是菜单选项本身，并且它不接受输入。如果它有所作为，我是第一次使用 Xcode，我需要它到运行，因为我的 Visual studio 版本不能运行 C++ （在 Mac 上）。我在这里哪里可能出错了，我对我的版本为什么错误的任何见解都表示赞赏，因为我对整体编码仍然很陌生。谢谢。

Answer 1

你有这个：

while (choice !=4);

这样一来，您的代码就不会继续执行此 while 循环。除非你的编译器在优化过程中删除了这一行。

正确的做法是：

    while (choice !=4) {
        switch (choice)
        {
            case 1:
                cout << "Monthly Payment Calculator:";
                cout << endl;
                break;
            case 2:
                cout << "Interest Rate Calculator:";
                cout << endl;
                break;
            case 3:
                cout << "Payment Term (In Months):";
                cout << endl;
            case 4:
                cout << "Exit Calculator:";

            default: //all other choices
                cout << "Please Select A Valid Option.";
                break;

        }
        cin >> choice; // have it right after the switch
   }

C++ 开关格式中的循环不允许我显示菜单选项或接受输入？

C++ The loop in my switch format isn't allowing me to display menu options or accept input?

c++

xcode

loops

menu

switch-statement