PowerShell function won't return empty array ever [duplicate]

Question

I want a function to always return an array, even if it's empty @(). I've noticed that just coercing the output of a function with @(MyFunction) will return an array with 1 element ($null) if the function returns $null. What I want is to coerce the result to empty array @() instead.

So how can we return an empty array from a function in PowerShell?

function ReturnAnEmptyArray() {return @()}
function ReturnNull() {return $null}

$a = @()
Write-Host "`$a is an empty array of length $($a.length) and type $($a.gettype())"
$b = ReturnAnEmptyArray
Write-Host "`$b is null: $($b -eq $null) but should be an empty array @()"
$c = @(ReturnNull)
Write-Host "`$c is an array of length $($c.length) and type $($c.gettype()) and `$c[0] is null $($c[0] -eq $null)"
$d = [array](ReturnNull)
Write-Host "`$d is just plain `$null $($d -eq $null) and not an array"

Output:

$a is an empty array of length 0 and type System.Object[]
$b is null: True but should be an empty array @()
$c is an array of length 1 and type System.Object[] and $c[0] is null True
$d is just plain $null True and not an array

Is there any sure way to have a function return an empty array??

function ConvertTo-Array($Obj) {
    # Return array as array
    if ($Obj -is [array]) {return $Obj}
    # Return $null as empty array @() => Fails to deliver @()
    elseif ($Obj -eq $null) {return @()}
    # Other values/objects (e.g. strings) are wrapped in an array
    else {return @($Obj)}
}

This might lead give you a direction: PS Doesn't return Empty Array as an Array — Ranadip Dutta
– Ranadip Dutta, Commented Mar 27, 2019 at 9:41

Ranadip Dutta · Accepted Answer · 2019-03-27 09:44:15Z

1

Quoting the same answer from Ansgar should help you in returning but its not a good way to deal

function returnemptyarray {
  $arr = @()
  return ,$arr
}

$a = returnemptyarray 
$a.gettype()

answered Mar 27, 2019 at 9:44

Ranadip Dutta

9,5493 gold badges33 silver badges48 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

PowerShell function won't return empty array ever [duplicate]

1 Answer 1

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Linked

Related