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Compiler Error CS0163

Visual Studio 2010

Updated: March 2012

Control cannot fall through from one case label ('label') to another

When a case statement contains one or more statements and is followed by another case statement, you must explicitly terminate the case by using one of the following keywords:

  • return

  • goto

  • break

  • throw

  • continue

If you want to implement "fall through" behavior, use goto case #. For more information, see switch (C# Reference)

The following sample generates CS0163:

Copy 
// CS0163.cs
public class MyClass
{
   public static void Main()
   {
      int i = 0;

      switch (i)   // CS0163
      {
         case 1:
            i++;
            // uncomment one of the following lines to resolve
            // return;
            // break;
            // goto case 3;

         case 2:
            i++;
            return;

         case 3:
            i = 0;
            return;
      }
   }
}

Date

History

Reason

March 2012

Replaced "continue" in the list of keywords with which you can end a switch section.

Customer feedback.

October 2010

Removed "continue" from the list of keywords that can be used to end a switch section.

Customer feedback.
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Annotations FAQ
About continue

To the Change History: The continue keyword can be used to exit the case block if the whole switch statement is inside a loop (that is, inside a for, foreach, while, or do body).$0 $0 By the way, another legal way to avoid fall-through, is like this:$0 $0 case 1:$0 while (true)$0 Console.WriteLine("Will this ever stop?");$0 //this point is unreachable$0 $0 /JeppeSN$0 $0 $0


Edit by SJ at MSFT: If you use the continue keyword, you exit from the loop iteration, not from the case or the switch statement. In this example:

int caseSwitch = 1;
for (int i = 0; i < 5; i++)
{
  switch (caseSwitch)
  { 
    case 1:
      Console.WriteLine("Case 1...");
      continue;
    case 2:
      Console.WriteLine("Case 2...");
      break;
  }
  caseSwitch += 1;
  Console.WriteLine("Out of switch but in loop");
}

The output is:
Case 1...
Case 1...
Case 1...
Case 1...
Case 1...
Variable caseSwitch is not incremented, and the last WriteLine is not executed.

Also, "while (true)" is valid but not very practical for most applications -- unless you have a lot of time on your hands.

Edit by Ben Voigt [Visual C++ MVP]: I fail to see why `continue` was removed from the list. Your reasoning is that it doesn't work like `break` and run the code following the switch? None of `return` or `throw` or `goto` continue execution following the switch either.

Edit by SJ at MSFT: Hmmmm, my example does resolve what would otherwise be a CS0163 error, which is the point here. I will look back through the history of the topic to see what occasioned the change. Perhaps I can rephrase.

History