Question

对于以下内容，我试图将用户输入限制为仅Y或y或N或n。请按照我对代码的评论，以便指出问题所在。我对这个论坛很新，我对编程有很大的热情，如果有人可以，请帮助我。谢谢。 while循环（不是do-while循环）是我遇到问题的部分。我想也许我没有正确使用！=。我还没有任何进展，我现在所在的课程只是入门级别。

    cout << "Would you like to use this program again?: ",
    cin >> ans;

    if(ans =='Y'||ans =='y'||ans =='N'||ans =='n')
        break;
    else //This is where I'm having problem with.
        while (ans != 'Y'||ans != 'y'||ans !='N'||ans !='n')
        {
            cout << "Please enter Y or y if you like to use the program again and N or n do exit.",
            cin >> ans; //If the question is asked and no matter what I input for ans, the while loop never gets exited. Why? Is there something I didn't use right?
        }
}while (ans == 'Y'||ans =='y');

return 0;

Answer 1

处理逻辑的更好方法是使用单个do循环，在他给出之前不断提示用户输入是/否输入：

do {
    cout << "Please enter Y or y if you like to use the program again and N or n do exit.",
    cin >> ans;
} while (ans != 'Y' || ans != 'y' || ans !='N' || ans !='n');

限制用户输入时遇到问题

1 个答案: