C ++投票程序帮助（初学者）！

Question

Im new at cpp and i try to train myself with a little voting program. You give in the parties and then the votes of the party.

#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;
}

So you see the while loop. I want the program stop if i only press enter. But when i do it nothing happens. Why? Give me a clue!

Answer 1

Change your input function so that it reads in the entire line via std::cin rather than a tokenized string. You'll need to consider this read method since there can be spaces in the instream. Also, your Wrong Input code fires when you just put a blank line.

Here's a fixed version:

#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;
}