How to test for $null array in PowerShell

Question

I\'m using an array variable in PowerShell 2.0. If it does not have a value, it will be $null, which I can test for successfully:

PS C:\\> [array]$foo =          


        

Answer 1

If your solution requires returning 0 instead of true/false, I've found this to be useful:

PS C:\> [array]$foo = $null
PS C:\> ($foo | Measure-Object).Count
0

This operation is different from the count property of the array, because Measure-Object is counting objects. Since there are none, it will return 0.