Question

I’m writing some code to figure out how to segment a list of values into more manageable chunks. the reason I want to do this is because I’ll have about 100,000 live values and I want to minimise the failure risk.

$wholeList = 1..100

$nextStartingPoint

$workingList

function Get-NextTenItems()
{
    $workingList = (1+$nextStartingPoint)..(10+$nextStartingPoint)

    $nextStartingPoint += 10

    Write-Host "inside Get-NextTenItems"
    write-host "Next StartingPoint: $nextStartingPoint"
    $workingList
    Write-Host "exiting Get-NextTenItems"
}

function Write-ListItems()
{
    foreach ($li in $workingList)
    {
        Write-Host $li
    }
}
Get-NextTenItems
Write-ListItems
Get-NextTenItems
Write-ListItems

I ran the code in the PowerGUI debugger and I’ve noticed my $nextStartingPoint is resetting to 0 when I exit the Get-NextTenItems function.

Why is this happening and how can I prevent it?

Should I also assume that the same thing is happening to $workingList?

Answer 1

In your example Get-NextTenItems changes its local variables. There are several ways to resolve this issue, here are two of them:

1) Specify the variable scopes explicitly (use prefix script or global). Namely, use that variables as $script:nextStartingPoint, $script:workingList inside the function.

2) Change the scope of the function on its call. Namely, call the function using the dot operator (“dot-source” the function), i.e. execute it in the current scope. This code works as expected (no other changes needed):

. Get-NextTenItems
Write-ListItems
. Get-NextTenItems
Write-ListItems 

See also

help about_scopes