Evaluate Expressions in Switch Statements in C#

I have to implement the following in a switch statement:

switch(num)
{
  case 4:
    // some code ;
    break;
  case 3:
    // some code ;
    break;
  case 0:
    // some code ;
    break;
  case < 0:
    // some code ;
    break;
}

Is it possible to have the switch statement evaluate case < 0? If not, how could I do that?

I know that this topic is pretty old but if someone still looking for the answer now in C# 7 it's possible. Here is an example:

switch (value)
{
     case var expression when value < 0:
         //some code
         break; 

     case var expression when (value >= 0 && value < 5):
         //some code
         break;

     default:
         //some code
         break;
}

Note: the answer below was written in 2009. Switch patterns were introduced in C# 7.

You can't - switch/case is only for individual values. If you want to specify conditions, you need an "if":

if (num < 0)
{
    ...
}
else
{
    switch(num)
    {
        case 0: // Code
        case 1: // Code
        case 2: // Code
        ...
    }
}

you can do this

switch (mark)
{
    case int n when n >= 80:
        Console.WriteLine("Grade is A");
        break;

    case int n when n >= 60:
        Console.WriteLine("Grade is B");
        break;

    case int n when n >= 40:
        Console.WriteLine("Grade is C");
        break;

    default:
        Console.WriteLine("Grade is D");
        break;
}