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Byref returned vs. Function returned

Maybe not everybody knows it, but standardly all arguments passed to a method are ByRef. This means if you change the value of this Variable, it will also change in the calling sub. Using this method you can make subs act like a function. But is it worth it... Well seems not, it's around 40% slower.

Code: Public Sub TestOne() Dim lngReturn As Long Call Function1(lngReturn) End Sub Public Sub TestTwo() Dim lngReturn As Long lngReturn = Function2 End Sub Private Sub Function1(Answer As Long) Answer = 100 * 55 End Sub Private Function Function2() As Long Function2 = 100 * 55 End Function

Function % faster than Byref	Function (sec)	Byref (sec)
54,3%	0,095617	0,147544
27,2%	0,104869	0,133398
51,2%	0,093329	0,141092
54,2%	0,096193	0,148360
36,3%	0,097453	0,132801

User contributed notes:

Author: PRoPHEZZoR ()	Date: 10:08 24/08/2004
Uh... You typed "ByRef % faster than Function" in that last table. You must be making a joke, it's the other way around ;-)
Author: Almar Joling ()	Date: 11:08 24/08/2004
fixed.
Author: Comintern ()	Date: 22:03 15/03/2005
Function calls reserve stack space for a return value, Subs do not.
Author: Tom (hurendo_kun at hotmail dot com)	Date: 16:06 08/06/2005
You're passing an argument to the first procedure, which slows it down. So, in this particular case, it's faster to make a function call with no arguments... but you may encounter a case where you need to use the argument in your algorithm and retrieve the result using the same argument, in which case the first method should be faster.
Author: TheShau (shauros at walla dot com)	Date: 15:08 04/08/2006
I've tested liek this, which seems more accurate. Public Sub TestOne() Dim lngReturn As Long Call Function1(lngReturn) End Sub Public Sub TestTwo() Dim lngReturn As Long lngReturn = Function2(lngReturn) End Sub Private Function Function1(Answer As Long) As Long Answer = 100 * 55 End Function Private Function Function2(Answer As Long) As Long Function2 = 100 * 55 End Function The tests produce the same times, except for incidental (1 out of 2 or 3) dramatic drops in run time (around 20-30%) for the byref version. I can't find a good explanation, but thought I might post it anyway.