Global scope, Local scope? What's the difference?

[sandman]

I don't have much experience in software programming, so forgive me for this n00bish question.

I read the help topic about Dim/Local/Global/Const, and wondered, why use local over global, or global over local?

All it says in the help file is that they use the global/local scope. What's the point of using these?

No very good results turned up on Google, either, so I came here.

Thanks,

SANDMAN!

[GEOSoft]

I don't have much experience in software programming, so forgive me for this n00bish question.

I read the help topic about Dim/Local/Global/Const, and wondered, why use local over global, or global over local?

All it says in the help file is that they use the global/local scope. What's the point of using these?

No very good results turned up on Google, either, so I came here.

Thanks,

SANDMAN!

I't well explained in the help file but in general it's this:

Global works throughout your entire script

Local works ony withing the function where it is declared.

A String that is declared prior to a function will be Global in nature without the scope being declared

In a script as follows

$G = "String"

Global $G = "String"

Func MyFunc()

Local $G = "SomethingElse"

EndFunc

The first two $G declarations are both Global

The $G within the function is Local in nature and will only be used within that function. It also has no effect on the Global $G.

[smashly]

Yep I'm a n00b still working it out slowly..

From my experiences:

Global I find is great when you need a variable that can be set and called from any function or loop in your entire script.

Local is good if your using a variable within a function and your not using that variable outside of the function.

I don't think it's a case of one being better to use over the other,

I think it's more a case of what your needs are in your script at the time and the amount of system resources your script is permitted to chew.

My 2 cents ..lol

Cheers

Edit I'm too slow to answer once again.. doh

Edited April 9, 2007 by smashly

[Richard Robertson]

Many people have requested File Local variables. These would be useful for UDFs that store information between calls. Global variables would work in the entire script, after it has been declared. Local variables work in their "scope" which is the area in which they were declared. File Local means it would only work in that file. Function Local only works in the function. If you declare a Local variable in a loop, I think it is also Loop Local.