A generalization of Switch

[DexterMorgan]

Switch says if variable x is v1 then do this, v2: do that and so on.
Is there a simple generalization that expresses: if x is in range [v1,v2] do something, if in [v3,v4] do something, if in [v5, v6]...

I can use if statements, but if can also be used in place of normal switch statements; Switch is a nice syntactic sugar.

Is there a nice way to do ranges?

[Peter87]

Well, you could list all the values in the range ...

switch (x)
{
case 1:
case 2:
case 3:
	// do something
	break;
case 4:
case 5:
	// do something else
	break;
}

... but that is only useful if the ranges are small, otherwise it's better to use if statements.

[dhayden]

There is no facility in the language to handle ranges, so you have to use if/then

Note that if the ranges partition the number space then you only need to check one value. For example, a common problem on these boards is converting a numeric grade to a letter grade:

if (num < 60) grade = 'F';
else if (num <70) grade = 'D';
else if (num < 80) grade = 'C';
else if (num < 90) grade = 'B';
else grade = 'A';

In some cases it might also be desirable to encode the ranges in data and use a little loop to find the appropriate range, then use a case statement to select what to do.

[m4ster r0shi]

Here's another idea:

#include <iostream>

int main()
{
    int a;

    std::cin >> a;

    switch ( (a >=  0 && a < 10)     +
             (a >= 10 && a < 20) * 2 +
             (a >= 20 && a < 50) * 3 )
    {
    case 1:
        std::cout <<  "[0, 10)" << std::endl;
        break;
    case 2:
        std::cout << "[10, 20)" << std::endl;
        break;
    case 3:
        std::cout << "[20, 50)" << std::endl;
        break;
    default:
        std::cout << "(-oo, 0) U [50, +oo)" << std::endl;
    }
}

I'd prefer if statements over this though.

[DexterMorgan]

I do like your solution m4ster r0shi :)