你如何有逻辑或万一的开关语句的一部分? [英] How do you have logical or in case part of switch statment?

问题描述

如果您有一个 switch 语句，并且希望在值为一个值时运行某些代码或另一个值，您该怎么做?以下代码始终使用默认情况.

If you have a switch statement and want certain code to be run when the value is one value or another how do you do it? The following code always goes to the default case.

#include <iostream>
using namespace std;

int main()
{
    int x = 5;
    switch(x)
    {
        case 5 || 2:
            cout << "here I am" << endl;
            break;
        default:
            cout << "no go" << endl;
    }

    return 0;
}

推荐答案

像这样:

switch (x)
{
case 5:
case 2:
    cout << "here I am" << endl;
    break;
}

被称为跌倒".

只是指出在发布的代码中执行 default 案例的原因是 5 || 的结果2 是 1 (true).如果您在发布的代码中将 x 设置为 1，则 5 ||2 案例将被执行(参见 http://ideone.com/zOI8Z).

Just to point out that the reason the default case is executed in the posted code is that the result of 5 || 2 is 1 (true). If you set x to 1 in the posted code the 5 || 2 case would be executed (see http://ideone.com/zOI8Z).

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