"Chip Pearson" wrote:

Kris,

Objects are always passed by reference. ByVal or ByRef indicates how the
pointer is passed to the function. If the pointer is passed ByRef, the
called procedure can change the object to which the argument refers and this
will be changed in the calling procedure. If the pointer is passed ByVal,
the object reference isn't changed in the calling procedure.

For example,

Sub Test1()
Dim Rng As Range
Set Rng = Range("A1")
Debug.Print "Before ByVal: " & Rng.Address
ByValExample Rng
Debug.Print "After ByVal: " & Rng.Address

Set Rng = Range("A1")
Debug.Print "Before ByVal: " & Rng.Address
ByRefExample Rng
Debug.Print "After ByVal: " & Rng.Address
End Sub

Sub ByValExample(ByVal R As Range)
Set R = Range("B1")
End Sub

Sub ByRefExample(ByRef R As Range)
Set R = Range("B1")
End Sub


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting
www.cpearson.com
(email on the web site)


"kris" wrote in message
...
How Workbook objects are passed into functions, is it passed as copy of
workbook or is passed as reference? please help me

Thanks Chip Pearson for ur very good example, but why workbooks can't be
passed as Byref. the following code is showing "ByRef Argument type mismatch"

Function func1(ByRef S1 As Workbook)
----------------
end Function

Sub ff()
dim D as workbook
set D=Application.WorkBook.open("C:\D.xls")
call func1(D)
end sub