filteringCollection.ps1

Invoke-RestMethod https://gist.githubusercontent.com/santisq/bd3d1d47c89f030be1b4e57b92baaddd/raw/236c79877ebaa75ce81c1806ef568d77abad6724/Measure-Expression.ps1 |
    Invoke-Expression

$range = [System.Linq.Enumerable]::Range(1, 100kb)

time @{
    'foreach + if' = {
        param($range)

        $result = foreach ($i in $range) { if ($i % 2) { $i } }
    }
    '.where' = {
        param($range)

        $result = $range.ToArray().Where({ $_ % 2 })
    }
    'where-object' = {
        param($range)

        $result = $range | Where-Object { $_ % 2 }
    }
    'process block + if' = {
        param($range)

        $result = $range | & { process { if ($_ % 2) { $_ } } }
    }
    'linq' = {
        param($range)

        $result = [System.Linq.Enumerable]::Where(
            $range,
            [Func[int, bool]]{param($e) $e % 2 }).
            ToArray()
    }
} -Parameters @{ range = $range }

result.md

Test                  Average RelativeSpeed
----                  ------- -------------
foreach + if         49.63 ms 1x
process block + if  176.45 ms 3.56x
.where              425.14 ms 8.57x
linq                557.04 ms 11.22x
where-object       1364.18 ms 27.49x