Switch case: can I use a range instead of a one number [duplicate]

Question

A bit late to the game for this question, but in recent changes introduced in C# 7 (Available by default in Visual Studio 2017/.NET Framework 4.6.2), range-based switching is now possible with the switch statement.

Example:

int i = 63;

switch (i)
{
    case int n when (n >= 100):
        Console.WriteLine($"I am 100 or above: {n}");
        break;

    case int n when (n < 100 && n >= 50 ):
        Console.WriteLine($"I am between 99 and 50: {n}");
        break;

    case int n when (n < 50):
        Console.WriteLine($"I am less than 50: {n}");
        break;
}

Notes:

• The parentheses ( and ) are not required in the when condition, but are used in this example to highlight the comparison(s).
• var may also be used in lieu of int. For example: case var n when n >= 100:.

Here is a better and elegant solution for your problem statement.

int mynumbercheck = 1000;
// Your number to be checked
var myswitch = new Dictionary <Func<int,bool>, Action>
            { 
             { x => x < 10 ,    () => //Do this!...  },  
             { x => x < 100 ,    () => //Do this!...  },
             { x => x < 1000 ,    () => //Do this!...  },
             { x => x < 10000 ,   () => //Do this!... } ,
             { x => x < 100000 ,  () => //Do this!... },
             { x => x < 1000000 ,  () => //Do this!... } 
            };

Now to call our conditional switch

   myswitch.First(sw => sw.Key(mynumbercheck)).Value();

Alternate for Switch/ifElse

To complete the thread, here is the syntax with C# 8 and C# 9 :

C# 8 syntax :

  var percent = price switch
  {
    var n when n >= 1000000 => 7f,
    var n when n >= 900000 => 7.1f,
    var n when n >= 800000 => 7.2f,
    _ => 0f // default value
  };

If you want to specify the ranges :

  var percent = price switch
  {
    var n when n >= 1000000 => 7f,
    var n when n < 1000000 && n >= 900000 => 7.1f,
    var n when n < 900000 && n >= 800000 => 7.2f,
    _ => 0f // default value
  };

C# 9 syntax :

  var percent = price switch
  {
    >= 1000000 => 7f,
    >= 900000 => 7.1f,
    >= 800000 => 7.2f,
    _ => 0f // default value
  };

If you want to specify the ranges :

  var percent = price switch
  {
    >= 1000000 => 7f,
    < 1000000 and >= 900000 => 7.1f,
    < 900000 and >= 800000 => 7.2f,
    _ => 0f // default value
  };

I would use ternary operators to categorize your switch conditions.

So...

switch( number > 9 ? "High" :
        number > 5 ? "Mid" :
        number > 1 ? "Low" : "Floor")
        {
              case "High":
                    do the thing;
                    break;
               case "Mid":
                    do the other thing;
                    break;
               case "Low":
                    do something else;
                    break;
               case "Floor":
                    do whatever;
                    break;
         }

If-else should be used in that case, But if there is still a need of switch for any reason, you can do as below, first cases without break will propagate till first break is encountered. As previous answers have suggested I recommend if-else over switch.

switch (number){
            case 1:
            case 2:
            case 3:
            case 4: //do something;
                    break;
            case 5:
            case 6:
            case 7:
            case 8:
            case 9: //Do some other-thing;
                   break;
        }