输入验证，需要数字而不是字符串..代码导致无限循环

Question

我试图弄清楚如何组织我的代码，以便在我测试它时停止导致无限循环。我输入了一个字符串，结果突然死循环了。

// 填写代码定义并初始化为1的变量month 浮动总计 = 0，雨，月 = 1；

cout << "Enter the total rainfall for month " << month << endl;
cout << "Enter -1 when you are finished" << endl;
// Fill in the code to read in the value for rain
cin >> rain;

// Fill in the code to start a while loop that iterates 
// while rain does not equal -1
if(cin.fail())
{
        cout << "You have inputted an invalid value." << endl << "Please enter an integer value for rain. (-1 to exit)";
        cin >> rain;
}
while (rain != -1)
{

    // Fill in the code to update total by adding it to rain
    // Fill in the code to increment month by one

    cout << "Enter the total rainfall in inches for month "
         << month << endl;
    cout << "Enter -1 when you are finished" << endl;
    // Fill in the code to read in the value for rain

Answer 1

如果 std::cin 接收到它无法解析的输入，它将设置一个故障位。您可以使用!cin 对此进行测试。勾选后不要忘记使用cin.clear重置failbit。