strange error

[keelaji]

HotKeySet ("{F10}", "Terminate")

Func Terminate()
    MsgBox( 0, "stop", "stopped")
    Exit
EndFunc   ;==>Terminate

 HotKeySet ("{1}", uno())
 HotKeySet ("{2}", due())

$a = 0

 Func uno()
     $a = WinGetHandle("")
 EndFunc

Func due()
    WinActivate($a)
EndFunc


While 1
WEnd

this code return this error whenever I call a function: 

"D:\autoit scripts\PROVA\prova.au3" (30) : ==> Variable used without being declared.:
WinActivate($a)
WinActivate(^ ERROR

what am I doing wrong ?

[SmOke_N]

You're declaring it after you set a function to call another function that calls it.

And to be honest, you're not  "really" declaring it.

This will work:

HotKeySet ("{F10}", "Terminate")

Func Terminate()
    MsgBox( 0, "stop", "stopped")
    Exit
EndFunc   ;==>Terminate


$a = 0

 HotKeySet ("{1}", uno())
 HotKeySet ("{2}", due())

 Func uno()
     $a = WinGetHandle("")
 EndFunc

Func due()
    WinActivate($a)
EndFunc


While 1
WEnd

 

But I'd expect to see something more like:

Global $a = 0
HotKeySet ("{F10}", "Terminate")
HotKeySet ("{1}", uno())
HotKeySet ("{2}", due())

Func Terminate()
    MsgBox( 0, "stop", "stopped")
    Exit
EndFunc   ;==>Terminate

 Func uno()
     $a = WinGetHandle("")
 EndFunc

Func due()
    WinActivate($a)
EndFunc

While 1
    Sleep(10)
WEnd

 

[keelaji]

5 minutes ago, SmOke_N said:

You're declaring it after you set a function to call another function that calls it.

And to be honest, you're not  "really" declaring it.

This will work:

HotKeySet ("{F10}", "Terminate")

Func Terminate()
    MsgBox( 0, "stop", "stopped")
    Exit
EndFunc   ;==>Terminate


$a = 0

 HotKeySet ("{1}", uno())
 HotKeySet ("{2}", due())

 Func uno()
     $a = WinGetHandle("")
 EndFunc

Func due()
    WinActivate($a)
EndFunc


While 1
WEnd

 

But I'd expect to see something more like:

Global $a = 0
HotKeySet ("{F10}", "Terminate")
HotKeySet ("{1}", uno())
HotKeySet ("{2}", due())

Func Terminate()
    MsgBox( 0, "stop", "stopped")
    Exit
EndFunc   ;==>Terminate

 Func uno()
     $a = WinGetHandle("")
 EndFunc

Func due()
    WinActivate($a)
EndFunc

While 1
    Sleep(10)
WEnd

 

Thank you smoke, it obviously works now.

I didn't quite understood the importance of Local and Global, because it seems working even if I don't use those.

[SmOke_N]

That's true, it will still work, any variable outside of a function is declared global and any inside a local.  But, it's bad practice in many eyes to just make yourself or others assume, plus other languages aren't so lenient.

It wasn't the declaration that fixed the issue, it was putting the variable above the function that called the function that used the variable.

eg.

Your hotkey calls "due()", due() uses the global variable $a, because the code works from the top down, due() was checked before the global variable $a was declared

[keelaji]

14 minutes ago, SmOke_N said:

That's true, it will still work, any variable outside of a function is declared global and any inside a local.  But, it's bad practice in many eyes to just make yourself or others assume, plus other languages aren't so lenient.

It wasn't the declaration that fixed the issue, it was putting the variable above the function that called the function that used the variable.

eg.

Your hotkey calls "due()", due() uses the global variable $a, because the code works from the top down, due() was checked before the global variable $a was declared

ok, thank you for your time.