RE: Declarations variables, Dim, some guidance please

Good coding practice is to use global or module level variable declarations
as little as possible. The big reason is that it makes the code very
difficult to debug. At any given time it can be difficult to know the value
of a variable because all procedures can access it. One small change to one
procedure can have side effects on all of the procedures that access that
variable. The problem is that when you make the change it is not at all
obvious what all of the consequences are. If you are passing the variable
then it is reasonalby obvious. The only reasons that I ever use Globals are:

1. I need a value determined at run time to persist. An example might be a
password to log into some subsystems. I get the user to enter it once and
that value is stored for as long as the program runs. Any time I need to log
into the subsystem I just call up the value. I don't have to worry about who
changed the value last becuase it is only set once at the beginning of
exectuion.

2. I have a function or sub procedure that is called repeatedly (great for
recursion). In order to speed up the exectution I will have it use global
variables so that the variables do not need to be created and destroyed each
time the procedure is called.
--
HTH...

Jim Thomlinson


"Neal Zimm" wrote:

> In an application that I'm developing I have dim'd quite a few variables in
> Declarations. I'll admit some of it is not wanting to take the time to put
> those vars that are used quite often in many macros within the sub
> SubName(var list) parenthesis.
>
> 1) What advice can you offer on the pro's and cons of this technique? All of
> the application's code is in ONE module.
>
> 2) I got 'bitten' when testing a macro where a var called Draw was dim'd as
> integer in Declarations, had a good value > 0 in prior macros, but was 0 in
> the macro I was testing.
>
> Sure enough, I had dim'd it again, inadvertantly, also as Integer in the
> macro being tested. Hence the 0 value, I guess. The QUESTION is, why did I
> NOT get a duplicate Dim error?
>
> Thanks.
> --
> Neal Z
.