Powershell inner collection iteration performance benchmark

benchmark.ps1

$complexObject = @{
    test = "test"
    guid = [guid]::NewGuid()
    int = [int]::MaxValue
    str = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum."
    arr = @(1..100)
}

$complexCollection = @()
$sw = [System.Diagnostics.Stopwatch]::StartNew()

Write-Host 'add the complex object to the complex array 10000 times.'
(1..10000) | % { $complexCollection += $complexObject }
Write-Host "adding the object 10000 times took $($sw.Elapsed)."

$sw.Restart()
$complexCollection | %{ $_.arr | % {$x = $_} }; $x = $null
$percentLoop = $($sw.Elapsed)

$sw.Restart()
$complexCollection | %{
    foreach($var in $_.arr){
        $x = $var
    }
}; $x = $null
$foreachLoop = $($sw.Elapsed)

$sw.Restart()
foreach($outer in $complexCollection){
    foreach($var in $outer.arr){
        $x = $var
    }
}
$fullForEach = $($sw.Elapsed)
$sw.Stop()

@{'ForEach' = $foreachLoop; 'percent (%)' = $percentLoop; 'full ForEach' = $fullForEach} | ft -AutoSize

result.txt

add the complex object to the complex array 10000 times.
adding the object 10000 times took 00:00:03.5356614.

Name         Value           
----         -----           
full ForEach 00:00:01.1445330
ForEach      00:00:01.5091856
percent (%)  00:00:20.0787455



A full foreach loop is definitively faster.