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redpicker

Help with defining variables

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redpicker

OK, this is a very basic programming question, but one that I am unsure of. I never had much formal programming training (and what I did have was mostly with Fortran - Watfor, actually) back in the 19-mumble-mumble's. I guess I am looking for some free education.
 

From what I can understand, it is good practice to define your variables at the start of the program. This I understand and makes sense and, like flossing, it's a pain, but I try to do it since I know it will make my life better in the long run.
 

Defining a "Global" variable means that the variable will be available to the code where it was defined as well as any other code called by the original code. This can create problems when a sub-routine is called that may use a variable defined as Global by the original program. A good example with AutoIT is using $i as a counter. If defined as a Global variable, and a routine or function is called that uses the same variable can alter its value unintentionally, with unpredictable results. Global variables do not have to be passed to these sub-routines in the function call.
 

A "Local" variable is essentially the opposite, that is, it is defined only in the original script and for the value of that variable to be used in a sub-routine, the value must be passed in the function call.
 

What if a variable is defined in a "Dim" statement? Is it Local or Global?
 

My immediate issues is that I am setting up a script that involves creating and defining a number of IE objects (not game related, in fact, it's work related, pretty much anti-game). To simplify my code, I would like to create a function to set-up all of these objects at the beginning. As there are over 20 of these objects, I really don't want to have to individually pass these variables in the function call, so how do I take care of it?

 

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BrewManNH

Don't use Dim because it can inadvertently re-declare a global variable if used in a function. ALWAYS use Global for variables used throughout the script, and Local for variables used inside the function it's declared in. Never use Global inside a function to declare a variable that is going to be used as a Global, declare them first then if you need to set a value to them in a function they're already declared. Doing it inside a function can lead to some tricky debugging being needed to fix an error with a variable that hasn't been declared yet.

ReDim is a special case and only used with Arrays.


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FireFox

Hi,
You can also take a look here.

Br, FireFox.


 

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redpicker

Thanks BrewMan and FireFox, just what I needed.

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