Format-Table not displaying in function

Question

I have a section of PowerShell code that reads a list of items from Azure, and formats them into a table for the user to choose from:

if ($SubscriptionArray.Count -eq 1) {
    $SelectedSub = 1
}
# Get SubscriptionID if one isn't provided
while ($SelectedSub -gt $SubscriptionArray.Count -or $SelectedSub -lt 1) {
    Write-host "Please select a subscription from the list below"
    $SubscriptionArray | Select-Object "#", Id, Name | Format-Table
    try {
        $SelectedSub = Read-Host "Please enter a selection from 1 to $($SubscriptionArray.count)"
    }
    catch {
        Write-Warning -Message 'Invalid option, please try again.'
    }
}

When executed in the main area of the script, this outputs the expected result:

I want to use this logic multiple times, and therefore moved it into a method:

function Get-IndexNumberFromArray(
    [Parameter(Mandatory = $True)]
    [array]$selectArray,

    [Parameter(Mandatory = $True)]
    [string]$message
) {
    [int]$SelectedIndex = 0
    # use the current subscription if there is only one subscription available
    if ($selectArray.Count -eq 1) {
        $SelectedIndex = 1
    }

    # Get SubscriptionID if one isn't provided
    while ($SelectedIndex -gt $selectArray.Count -or $SelectedIndex -lt 1) {
        Write-Host "$message"

        $selectArray | Select-Object "#", Id, Name | Format-Table

        try {
            $SelectedIndex = Read-Host "Please enter a selection from 1 to $($selectArray.count)"
        }
        catch {
            Write-Warning -Message 'Invalid option, please try again.'
        }
    }

    return $SelectedIndex
}

Everything in this method works great, except now my table is no longer outputting to the window. Instead, the user just get a prompt to pick a number from 1 to x with no context for what each number represents.

Why is the table working in the main area of the script, but not working in a function?

Answer 1

Format-Table actually doesn't print a table, it outputs objects that are then printed as the table. So if you're using a function, then the Format-Table output gets part of the return value of your function.

You can add Out-Host to the pipeline to force Format-Table's result to end up on the host, i.e. the console:

$selectArray | Select-Object "#", Id, Name | Format-Table | Out-Host