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crez

Senior Member

Joined: 24/10/2012
Location: Australia
Posts: 152

Posted: 08:40pm 04 Jun 2021

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running the following

Option explicit
Dim a As integer
s1
End

Sub s1
Local b As integer
s2
End Sub

Sub s2
Local c As integer
a=1
b=1
c=1
End Sub

gives the error 'b is not declared' at line 14.
because sub s2 is called from within s1, I was expecting b would be declared, in the same way that a is available in s1. Apparently not. If I declare b in sub s1 using the DIM command, it becomes available in sub s2 but also the main program, which is not what I desired.

CaptainBoing

Guru

Joined: 07/09/2016
Location: United Kingdom
Posts: 2171

Posted: 08:51pm 04 Jun 2021

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DIMed variables are global no matter where they are declared

I use this with my VB-a-like Split function. Because an array cannot be REDIMed, I ERASE it then DIM it inside a Function expecting it to be available outside the Sub/Function.

In the red boxes, the array is ERASEd and then DIMed in one of two places. The new array becomes available outside the Function. This simulates the VB REDIM statement.

If you only want that variable for s2, you can pass it in as an argument when you call it:

Sub s2(b as integer)
Print b

you then have a "b" variable available just to s2
.
Edited 2021-06-05 07:02 by CaptainBoing

JohnS
Guru

Joined: 18/11/2011
Location: United Kingdom
Posts: 4147

Posted: 09:34pm 04 Jun 2021

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crez said running the following

Option explicit
Dim a As integer
s1
End

Sub s1
Local b As integer
s2
End Sub

Sub s2
Local c As integer
a=1
b=1
c=1
End Sub

gives the error 'b is not declared' at line 14.

LOCAL means lexically scoped to the enclosing SUB (or FUNCTION), as you've discovered.

(Many other languages do it that way, too.)

So, b is visible inside s1 but nowhere else.

John
Edited 2021-06-05 07:35 by JohnS

crez

Senior Member

Joined: 24/10/2012
Location: Australia
Posts: 152

Posted: 03:29am 05 Jun 2021

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Thanks Captain and John.
I'm a bit surprised this didn't trip me up earlier. Hopefully I remember it for next time

.I have it working as I wanted by DIM at the start of the sub and ERASE at the end.

David

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