switch

#include <iostream>

using namespace std;

int main()
{
    unsigned char input_char = 0;

    cout << "Please input a character to start." << endl;
    cin >> input_char;
    while (input_char != 'q')
    {
        switch (input_char)
        {
        case 'a':
        case 'A':
            cout << "Move left. Input 'q' to quit." << endl;
            break;
        case 'd':
        case 'D':
            cout << "Move right. Input 'q' to quit." << endl;
            break;
        default:
            cout << "Undefined key. Input 'q' to quit." << endl;
            break;
        }
        cin >> input_char;
    }
}