[RESOLVED] newbie help

[Aash]

Hi
I'm newbie in visual basic. I'm having problem in understanding functions (byval & byref). I have surfed on the internet but i found no useful link for that. Will anyone provide me some links please..



Thanks in advance.

[Ellis Dee]

ByVal means to pass by value. This means a copy of the variable is sent to the function. ByRef means pass by reference. A "pointer" to the variable is sent to the function, so if you assign a new value to the passed parameter in the called function, the variable from the calling function is changed, too. Because ByRef parameters are just "pointers", the variable datatype must be an exact match. When you pass variables ByVal the dataype doesn't have to match because VB does implicit coercion.

[Aash]

Thanks for the reply Ellis
So in Byval values can be changed and in Byref can't?
can both Byref and Byval be used in the same user-defined function??
like this..

Private function Add(Byref a as integer, Byval b as integer)

if so, will u explain it?

[Ellis Dee]

All values can be changed, the difference is that changes to ByVal parameters get discarded once the function ends while changes to ByRef parameters are saved even after the function ends.

Yes, both types can be used in the same function.