似乎无法使我的IF语句正常工作

时间:2013-11-11 19:17:11

标签: c++ if-statement conditional-statements conditional-operator

我似乎无法将这些if语句按预期工作。 无论我输入“字符串答案”,它总是跳转到第一个IF语句,其中条件设置为仅在答案正好为“n”或“N”时执行块或者答案恰好为“y”的块或“Y”。如果您输入任何其他内容,则应返回0。

    // Game Recap function, adds/subtracts player total, checks for deposit total and ask for another round
    int gameRecap() {
    string answer;
    answer.clear();

    cout << endl << "---------------" << endl;
    cout << "The winner of this Game is: " << winner << endl;
    cout << "Player 1 now has a total deposit of: " << deposit << " credits remaining!" << endl;
    cout << "-------------------------" << endl;

    if (deposit < 100) {
       cout << "You have no remaining credits to play with" << endl << "Program will now end" << endl;
       return 0;       
    }
    else if (deposit >= 100) {
       cout << "Would you like to play another game? Y/N" << endl;
       cin >> answer;
       if (answer == ("n") || ("N")) {
          cout << "You chose no" << endl;
          return 0;
       }
       else if (answer == ("y") || ("Y")) {
          cout << "You chose YES" << endl;
          currentGame();
       }
       else {
            return 0;
       }
       return 0;
    }
    else {
         return 0;
    }
return 0;
}

3 个答案:

答案 0 :(得分:9)

这是不正确的:

if (answer == ("n") || ("N"))

应该是

if (answer == "n" || answer == "N")

找出当前代码编译的原因是有益的:在C ++和C中,隐式!= 0被添加到不表示布尔表达式的条件中。因此,表达式的第二部分变为

"N" != 0

总是true"N"是一个字符串文字,永远不会是NULL

答案 1 :(得分:5)

||运算符不会像您认为的那样工作。

if (answer == ("n") || ("N"))

正在检查answer是否为"n",如果不是,则将"N"评估为布尔值,在这种情况下始终为真。你真正想做的是

if (answer == ("n") || answer == ("N"))

您还应针对"y""Y"进行类似的调整。

答案 2 :(得分:2)

此部分未正确评估:

if (answer == ("n") || ("N")) {}

Shold be:

if (answer == "n" || answer == "N") {}