C++投票程序求助(初学者)!

Question

我是 cpp 的新人，我尝试通过一个小投票程序来训练自己。您先让出政党，然后再让出政党的选票。

#include<iostream>
#include<string>

using namespace std;

int main()
{
    string sInput = " ";
    string sName1 = " ";
    string sName2 = " ";
    int iParty1 = 0;
    int iParty2 = 0;

    cout << "Name of the first party: ";
    cin >> sName1;
    cout << "Name of the second party: ";
    cin >> sName2;

    while (sInput != "")
    {
        cout << "Your vote: ";
        cin >> sInput;
        cout << endl;
        if (sInput == sName1)
        {
            iParty1++;
        }
        else
        {
            if (sInput == sName2)
            {
                iParty2++;
            }
            else
            {
                cout << "Wrong Input" << endl;
            }
        }

    }
    cout << sName1 << ": " << iParty1 << endl;
    cout << sName2 << ": " << iParty2 << endl;
    getchar();
    return 0;
}

所以你看到了 while 循环。如果我只按回车键，我希望程序停止。但是当我这样做时什么也没有发生。为什么？给我一个线索!

Answer 1

更改您的输入函数，使其通过 std::cin 而不是标记化字符串读取整行。您需要考虑这种读取方法，因为流内可能有空格。此外，当您输入一个空行时，您的错误输入代码将被触发。

这是一个固定版本:

#include<iostream>
#include<string>

using namespace std;

int main()
{
    string sInput = " ";
    string sName1 = " ";
    string sName2 = " ";
    int iParty1 = 0;
    int iParty2 = 0;

    cout << "Name of the first party: ";
    cin >> sName1;
    cout << "Name of the second party: ";
    cin >> sName2;
    cin.ignore();

    while (sInput != "")
    {
        cout << "Your vote: ";
        getline(cin, sInput);
        cout << endl;
        if (sInput == sName1)
        {
            iParty1++;
        }
        else
        {
            if (sInput == sName2)
            {
                iParty2++;
            }
            else
            {
                cout << "Wrong Input" << endl;
            }
        }

    }
    cout << sName1 << ": " << iParty1 << endl;
    cout << sName2 << ": " << iParty2 << endl;
    getchar();
    return;
}