How do you have logical or in case part of switch statment?

Question

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;
}

Answer 1

Like this:

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

Known as "falling through".

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).

Answer 2

Make it fall through:

int main()
{
    int x = 5;
    switch(x)
    {
        case 5:
        // there's no break statement here,
        // so we fall through to 2
        case 2:
            cout << "here I am" << endl;
            break;
        default:
            cout << "no go" << endl;
    }

    return 0;
}

5 || 2, by the way, evaluates to 1 (or true, as it is a logical expression), you can try it.