Returning early from a function in classic ASP

Question

Is there a way to return early from a function in classic ASP rather than it run the full length of the function? For example lets say I have the function...

Function MyFunc(str)
  if (str = "ReturnNow!") then
    Response.Write("What up!")       
  else
    Response.Write("Made it to the end")     
  end if
End Function

Can I write it like so...

Function MyFunc(str)
  if (str = "ReturnNow!") then
    Response.Write("What up!")       
    return
  end if

  Response.Write("Made it to the end")     
End Function

Note the return statement which of course I can't do in classic ASP. Is there a way to break code execution where that return statement sits?

Answer 1

Yes using exit function.

Function MyFunc(str)
  if str = "ReturnNow!" then
    Response.Write("What up!")       
    Exit Function
  end if

  Response.Write("Made it to the end")     
End Function

I commonly use this when returning.

Function usefulFunc(str)
   ''# Validate Input
   If str = "" Then
      usefulFunc = ""
      Exit Function
   End If 

   ''# Real function 
   ''# ...
End Function

Answer 2

With classic ASP, you need to use Exit Function:

Function MyFunc(str)
  if (str = "ReturnNow!") then
    Response.Write("What up!")       
    Exit Function
  end if

  Response.Write("Made it to the end")     
End Function

Answer 3

As has been pointed out you can use Exit Function but you should use caution. In the simple example you gave there really is no advantage no other code would have executed anyway.

Placing exit points throughout a chunk of code can make it hard to follow and debug. More seriously it can lead subsequent changes to the code being harder, requiring more extensive changes and therefore increasing the risk. Hence such a pattern should be considered a "bad smell".

A typical scenario where its reasonably acceptable is where the code may make some assertions on its input parameters before continuing with the body of the code. Other than that you should be able to express a really, really good reason to do it.

You may say "If I do it that way I'll have more If structures and increase the identation in the code excessively". If that is so then the function has too much code in it anyway and should be refactored into smaller functions.