Increment a variable?

[robotman]

Is there a way to write a function to increment a variable (i.e. to
replace "myvar = myvar + 1")?

For example, I would like to create a custom function called "inc" so I
can do:

inc myvar

This would require somehow passing a variable name to the function
(which I don't see how is possible).

Any other ideas how to get around the "myvar = myvar + 1" ?

Thanks!

 

[JE McGimpsey]

One way:

Public Function inc(ByRef vIn As Variant)
If IsNumeric(vIn) Then vIn = vIn + 1
End Function

 

[robotman]

Maybe I'm misunderstanding something, but I wanted to create a function
that you could pass any variable to and have it increment that
variable:

inc myvar1
inc myvar2
inc myvar3

Wouldn't JE's example just increment a variable called "vln"?

I also know it's a small performance hit, but for speed in coding, it's
worth it to me.

Thanks!

 

[JE McGimpsey]

No.

When you call inc using

inc myvar1

then myvar1 is passed by reference to inc, and will be assigned the
value that is assigned to vIn.

From XL/VBA Help ("by reference"):

a way of passing the address of an argument to a
procedure instead of passing the value. This allows
the procedure to access the actual variable. As a
result, the variable's actual value can be changed
by the procedure to which it is passed. Unless
otherwise specified, arguments are passed by reference.

 

[robotman]

I've been programming for 17 years and have misunderstood ByRef the
whole time. I thought it meant that you could modify the variable and
keep the new value ONLY if you passed the same name into the procedure.

Ex.

myvar = 4

sub inc(byref myvar as integer)
myvar = myvar + 1
end sub

-> myvar = 5

I didn't know you could call the sub variable anything you want in the
procedure and the sub variable would still point back to the orignal
variable.

Since ByRef is default, I don't quite understand how I've called 1000's
and 1000's of subs, passed variables, used them in calculations, and
then continue the main sub without that variable causing problems. The
only thing I can think of is that I must be assigning the variables
right before I pass them so even though they're getting changed, I
reassign the correct value before calling the sub again.

Very interesting discovery in terms of never causing problems in my
programming.

Thanks for your BASIC insight...