Persistent Realities » Home

Site
News
Files

Visual Basic
Strings
Math
General
Properties
Memory
Methods

Inline ASM-VB
Strings
Math
General
Memory

Early vs. Late binding

Well, the difference is really unproportional =-) Just to make something clear:

Early binding: Checking the object under "references" and use "Dim X as ObjectName"
Late binding: Using "Dim X as Object" and later "Set X = CreateObject("ObjectName")

I made a small ActiveX dll with the following code:

Code: Public Function PerformCalculation(lngValue1 As Long, lngValue2 As Long) As Long PerformCalculation = lngValue1 lngValue2 End Function

Then I referenced one variable using "References". Then I set the variables correctly in the Declaration section:

Declarations: Private objTest1 As Object Private objTest2 As VbFibreTest.clsCalc

Their instance was created using:

Code: '//Create objects Set objTest1 = CreateObject("VbFibreTest.clsCalc") Set objTest2 = New clsCalc

And finally this was called 5x500.000 times:

Code: Public Sub TestOne() Dim lngReturn As Long lngReturn = objTest1.PerformCalculation(100, 50) End Sub Public Sub TestTwo() Dim lngReturn As Long lngReturn = objTest2.PerformCalculation(100, 50) End Sub

Late % faster than Early	Late (sec)	Early (sec)
3772,6%	6,404157	0,165373
3818,2%	6,454636	0,164735
3792,6%	6,378763	0,163867
3498,2%	6,396008	0,177755
3573,8%	6,406381	0,174380

User contributed notes:

Author: VBBR ()	Date: 23:03 20/03/2004
And are there any speed differences between Dim a as SomeThing 'later on... Set a = New SomeThing and Dim a as New SomeThing ???
Author: VBBR ()	Date: 22:03 31/03/2004
Oh, I just saw a separate test for that, sorry.
Author: Tom (hurendo_kun at hotmail dot com)	Date: 04:09 23/09/2005
Late-binding also occurs when you declare "Dim obj as Object" and set it later with "Set obj = New objType." Using the CreateObject function will make it considerably slower because not only is it a function call, but it has to look up the object definition in the type library. Maybe you should add a third test to the mix?