By val or By ref

[qassim]

Hello,
Can any one tell me how to use
both in function and what is the diffrece
and plz with example
Bye

Byval makes a duplicate of the value you are passing and drops it into the variable name.

Byref just invents an address in memory where the value can be found when needed.

i don't think and code samples would be much help, since they both look very similar.

Byref is slower but takes less memory, and byval is usually faster but has the drawback of using more memory.

For example, you probably wouldn't use byval for very large strings, because you would instantly clog up some more memory.

[parksie]

If not specified, VB uses ByRef as the default.

[Sam Finch]

I think Wossname covered the main differences,

as a code example say you had this sub

Public Sub Augment(Number As Long)

Number = Number + 1

End Sub

now try this code

Dim a As Long

a = 4

Call Augment(a)

Msgbox a

as parksie said
by default the value is passed byref but add the ByRef Keyword to the augment function anyway and run the code.

you should get a messagebox with a 5 in it

now change it to ByVal

you get a messagebox with a 4 in it

the reason for this is that if you pass a variable byval you cannot change its value outside the sub because you are not passed the variable itself, you are passed a copy of its value.

hope that helps