Switch Statement in C#

Question

Does anyone know if it's possible to include a range in a switch statement (and if so, how)?

For example:

switch (x)
{
   case 1:
     //do something
     break;
   case 2..8:
     //do something else
     break;
   default:
     break;
}

The compiler doesn't seem to like this kind of syntax - neither does it like:

case <= 8:

Answer 1

No, this isn't possible. There are a few ways I've done this in the past:

Fixed coding:

switch (x)
{
   case 1:
     //do something
     break;
   case 2:
   case 3:
   case 4:
   case 5:
   case 6:
   case 7:
   case 8:
     //do something else
     break;
   default:
     break;
}

In combination with an if {} statement:

switch (x)
{
   case 1:
     //do something
     break;
   default:
     if (x <= 8)
     {
        // do something
     }
     else
     {
       // throw exception
     }
     break;
}

Answer 2

No, but you can write this, so you at least avoid writing the // do something else part multiple times.

switch (x)
{
   case 1:
     //do something
     break;
   case 2: case 3: case 4: case 5: case 6: case 7: case 8:
     //do something else
     break;
   default:
     break;
}

Answer 3

Whilst this wasn't possible when I originally asked this question, through the miracle of C# Pattern Matching, it now is (in C# 7):

switch (i)
{
    case var test when test <= 2:
        Console.WriteLine("Less than 2");
        break;

    case var test when test > 2 && test < 10:
        Console.WriteLine("Between 2 and 10");
        break;

    case var test when test >= 10:
        Console.WriteLine("10 or more");
        break;
}

A blog post on the subject

Answer 4

Short answer : no. It would be possible to write all of the cases there but such a range notation is not supported.

I think you have to use if statement here or switch to a language where there is a better support for case descrimination.

Answer 5

One possibility is to convert your ranges into integers. For example:

//assuming x>=9 or if (x <= 0) return;
        switch((x+12)/7)
        {   case 1:Console.WriteLine("one");
                break;
            case 2:Console.WriteLine("2 through 8 inclusive");
                break;
            case 3:Console.WriteLine("9 through 15 inclusive");
                break;
            default: Console.WriteLine("16 or more");
                break;
        }

Answer 6

If you have so few cases, if would be much preferred.

Answer 7

You could, handle the explicit cases case by case, and if you only have one range, deal with it in the default case.

Answer 8

you can do

case 2:
case 3:
case 4:
...
case 8:
 // code here
 break

Answer 9

You can use case fall through:

switch (x)
{
   case 1:
     //do something
     break;
   case 2:
   case 3:
   case 4:
   case 5:
   case 6:
   case 7:
   case 8:
     //do something else
     break;
   default:
     break;
}

But I'd just use if for this.

Answer 10

You cannot use any conditional statements in a switch case.

If you want to execute the same lines of code for different options then you can do one thing:

switch (i)
            {
                case 0:
                case 1:
                case 2: 
                case 3:
                    //do something here.
                    break;
                default:
                    //do something here.
                    break;
            }