Declaring Global Variables

[DigDeep]

Hi,

I am facing some issues with Global variables in my code.

If I have assigned a variable as GLOBAL at the top of the code, is it again required to re-declare the same as GLOBAL $Variablename in between the code whereever I am using $Variablename?

I am finding out that I am not declaring the Global again in between the code, then it does not do the checks.

[DigDeep]

just to give a small example...

Say if I have given as per below, if I am not declaring Global $Variable1 = Filepath before the re-check, it gives me result as Failed instead of Passed, even if the Func did worked.

 

Global $Variable1 = Filepath

Func First_Part()
    Code here...
Endfunc

While 1
    Select
     Global $Variable1 = Filepath   
        Case Fileexists = $Variable1
            First_Part()
    Endselect
    
    Select
        Case Fileexists = $Variable1 ; Do re-check
            MsgBox(0, "", "Passed")
        Case else
            MsgBox(0, "", "Failed")
    Endselect  
Wend

 

 

 

 

 

Edited January 10, 2016 by DigDeep

[InunoTaishou]

I would check out declaring variables from the help file

https://www.autoitscript.com/autoit3/docs/keywords/Dim.htm

[czardas]

You only have to declare a global variable once. The reproducer code you posted does not run and it does not clearly demonstrate your problem.

Global $Variable1 = "before"

MsgBox(0, "Msg1", $Variable1)

$Variable1 = "after" ; do not edeclare a global variable

MsgBox(0, "Msg2", $Variable1)

In your code, the Select statement is also wrong. You should follow Select immediately with the first Case statement. In addition, do not declare variables in a loop unless you know what you are doing.

Edited January 10, 2016 by czardas

[DigDeep]

@czardas It was just a dummy example I was giving above to show what I was doing. What I wanted to mention was that when am declaring a variable as Global at the top of the script, if I do not re-declare within the While loop inside the Case statements, instead of Passed it gives me a Failed message.

When I tried to re-declare again inside every "Case", it works good.

just wanted to know how and where to declare a Global variable that I do not have to re-declare them again within  func or inside loop multiple times.

also, what is the difference between Global and Dim?

 

[czardas]

If I try and run your code, I get failed code execution messages, so I have no idea how to fix your problem. I will repeat - never redeclare a global variable.

Dim is a depreciated keyword, but remains in the language for backwards compatibility. Some people still use it to empty the contents of an array. Dim can be either local or global.

Why not post all your code so we can look for your problem?

Edited January 10, 2016 by czardas

[TheSaint]

In short, once you declare a variable as Global, then whatever value you assign to the variable afterward is available to code anywhere in your script ... and you can keep changing it, and that new value is global automatically.

For me, this where the simplicity of just declaring a variable at the start of your script, without assigning anything to it, is no doubt less confusing to a beginner. You do however reduce your code and typing by combining both.

Global $Variable1

$Variable1 = Filepath

Func First_Part()
    Code here...
Endfunc

While 1
    Select
        $Variable1 = Filepath   
        Case Fileexists = $Variable1
            First_Part()
    Endselect
    
    Select
        Case Fileexists = $Variable1 ; Do re-check
            MsgBox(0, "", "Passed")
        Case else
            MsgBox(0, "", "Failed")
    Endselect  
Wend

Look at that declared variable on its own as a placeholder that is Global, which can have a value assigned to it at any time, and is part of the global arrangement.

But in your case, you could just do the following

Global $Variable1 = Filepath

Func First_Part()
    Code here...
Endfunc

While 1
    Select
        $Variable1 = Filepath   
        Case Fileexists = $Variable1
            First_Part()
    Endselect
    
    Select
        Case Fileexists = $Variable1 ; Do re-check
            MsgBox(0, "", "Passed")
        Case else
            MsgBox(0, "", "Failed")
    Endselect  
Wend

I have not checked for any errors in the rest of your code.

Edited January 10, 2016 by TheSaint

[czardas]

I missed something earlier.

Case Fileexists = $Variable1 ; this is nonsense

Case FileExists($Variable1) ; this is the correct test