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c++ - Unknown behaviour of OR operator in C++

问题描述

I have this code running by chance and when i put anything as the answer it is showing me correct. I know we have to put ans before YES and yay, but this code was compiled too, as i mentioned if i put any word as the input the output is correct:

string ans;
cin >> ans;

if(ans == "yes" || "YES" || "yay") {
    cout << "Correct";
}else {
    cout << "Incorrect";
}

标签： c++logic

解决方案

好的，这是逻辑运算符的优先级（L->R）和关联性：

(((ans == "yes") || "YES") || "yay")

由于 C/C++没有与 Python 不同的链接。

第一个：ans == "yes"->str比较str

第二：bool result of 1st || "YES"-> bool和str比较=总是true为"YES"不为空

第三：true || "YES"=总是true

因此，条件将始终为truefor"YES"且不为"yay"null。

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