Mastering Windows PowerShell Scripting - Third Edition

Removing elements from an array

Removing elements from an array is difficult because arrays are immutable. To remove an element, a new array must be created.

It is possible to appear to remove an element by setting it to null, for example:

$myArray = 1, 2, 3, 4, 5 
$myArray[1] = $null 
$myArray 

However, observe that the count does not decrease when a value is set to null:

PS> $myArray.Count 5

Loops (or pipelines) consuming the array will not skip the element with the null value (extra code is needed to guard against the null value):

$myArray | ForEach-Object { Write-Host $_ } 

The Where object may be used to remove the null value, creating a new array:

$myArray | Where-Object { $_ } | ForEach-Object { Write-Host $_ } 

Depending on usage, a ...