Counting issue with variables

[JorisK1980]

Product, version and build: 4.2.99
32 or 64 bit version of product: 64
Operating system: W2012R2
32 or 64 bit OS: 64
PowerShell Version: 4

Hi,

1) I have in globals $i = 1
2) I have button1 that does $i++
3) I have button2 that does write-host $i

When i press Button 1 several times, i would assume that $i have a higher value then 1, but when i hit button 2, it outputs "1".

I have this issue now with a script that used to work fine for years, and now all of a sudden i have this issue.

Anyone any clue? Something simple like this should be working imho...

[DevinL]

[TOPIC MOVED TO POWERSHELL GUIS FORUM BY MODERATOR]

[skalizar]

Most likely a scope issue. You've declared a global variable, but the $i you are incrementing in the button event is local.

[jvierra]

$global:i++

When a variable is written to in an inner scope a new local variable is created. To avoid this specify the full scope of the variable.

see - help about_scopes

Global variables should be avoided except in very specific cases.

[DevinL]

Another option could be to use the $script:i++ scope since the form is a single script file it shouldn't be necessary to use the global scope.

That being said, I'm making the assumption that when you say "1) I have in globals $i = 1" you really mean in your globals.ps1 file you have $i = 1 and you're referencing it from a form within your project.

If you're actually assigning $i to the global scope, then you'll have to do what Jvierra said with $global:i++.

[JorisK1980]

Thanks a lot guys, it seems to work.

I have always worked with simply $i++, i don't have a problem to now use $script:i++ but can anyone explain to me why my old way of defining $i all of a sudden doesn't work anymore? This script has worked for years.

Anyways, many thanks!

[jvierra]

When in a form you are in a sub-scope. "global" is in the global scope. You cannot directly change a variable in an outer scope without referencing the scope it is contained in.

See help about_scopes for a complete explanation.

This could never have worked for years as PowerShell is not designed that way. THIs is how all nearly programming languages work. It is fundamental.

[jazz albert]

I think there must some way to get it done!