C++ Noobie - 为什么移动这些行会破坏我的应用程序？

Question

这是我对 C++ 的第一次尝试，下面是一个通过控制台应用程序计算小费的例子。完整(工作代码)如下所示:

// Week1.cpp : Defines the entry point for the console application.

#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
    // Declare variables
    double totalBill = 0.0;
    double liquour = 0.0;
    double tipPercentage = 0.0;
    double totalNoLiquour = 0.0;
    double tip = 0.0;
    string hadLiquour;

    // Capture inputs
    cout << "Did you drink any booze? (Yes or No)\t";
    getline(cin, hadLiquour, '\n');

    if(hadLiquour == "Yes") {
        cout << "Please enter you booze bill\t";
        cin >> liquour;
    }

    cout << "Please enter your total bill\t";
    cin >> totalBill;

    cout << "Enter the tip percentage (in decimal form)\t";
    cin >> tipPercentage;

    // Process inputs
    totalNoLiquour = totalBill - liquour;
    tip = totalNoLiquour * tipPercentage;

    // Output
    cout << "Tip: " << (char)156 << tip << endl;
    system("pause");

    return 0;
}

这很好用。但是，我想移动:

cout << "Please enter your total bill\t";
cin >> totalBill;

成为第一行:

 // Capture inputs

但是当我这样做时应用程序中断(它编译，但只是忽略 if 语句然后同时打印两个 cout。

我抓耳挠腮，因为我不明白发生了什么 - 但我假设我是个白痴!

谢谢

Answer 1

试试这个

    // Capture inputs
cout << "Please enter your total bill\t";
cin >> totalBill;
cin.clear();
cin.sync();

参见 c++ getline() isn't waiting for input from console when called multiple times

或者，最好根本不使用 getline:

cout << "Please enter your total bill\t";
cin >> totalBill;

cout << "Did you drink any booze? (Yes or No)\t";
cin >> hadLiquour;