C ++ if / else if语句

Question

我正在制作关于Cramer规则和矩阵的程序（太多空闲时间）。在某个地方，我有这个问题，你需要输入“是”或“否”。如果我输入其他单词（例如lol），它将不会转到if语句或再次提出问题。如何将答案限制为是/否？

cout << "There! you have now your first equation! is it " << a << "x+"   << b << "y=" << e << "? Is it? Yes/No"<<endl;
cin >> z;
if ( z== "No" )
    {
        while ( z== "No" )
            {
                cout << "what is the value of x?"<<endl;
                cin >> a;
                cout << "\n"<<endl;
                cout << "what is the value of y?"<<endl;
                cin >> b;
                cout << "\n"<<endl;
                cout << "what is the value of answer?"<<endl;
                cin >> e;
                cout << "\n"<<endl;
                cout << "There! you have corrected your first equation! is it " << a << "x+" << b << "y=" << e << "? Is it? Yes/No"<<endl;
                cin >> z;
            }
    }
else if ( z== "Yes" )
    {
        cout << "We will now proceed!"<<endl;
    }

我只是c ++的初学者 使用代码块

Answer 1

阅读do while循环！这是一个后测试循环，因此您可以验证z是或否。 http://www.cplusplus.com/doc/tutorial/control/

基本思路是： 当用户输入不等于是或否时，用户输入。

基本示例：

int x;
do {
    cout << "Please enter 1 or 0" << endl;
    cin >> x;
} while (x != 0 && x != 1);