Custom object array element with minimum / maximum value of some property - powershell

Question

$CustomObjects = Get-Random -Count 7 -InputObject #(0..300) | ForEach-Object {$i = 0} {
[PSCustomObject]#{
id = ($i++)
value = $_
}
}
$min, $max = & {$Args[0].Minimum, $Args[0].Maximum} ($CustomObjects | ForEach-Object value | Measure-Object -Minimum -Maximum)
$CustomObjects | Format-Table id, value -RepeatHeader
$CustomObjects | Where-Object {$_.value -eq $min} | Format-Table id, value
$CustomObjects | Where-Object {$_.value -eq $max} | Format-Table id, value
Are there more interesting options for finding the minimum / maximum?

Answer 1

We could come up with a long list of valid PowerShell statements that all look slightly different and would yield the same result, but there's basically 2 ways:
Sorting
Keeping count
Obtaining min/max through sorting is exactly what it sounds like:
$min,$max = #($CustomObjects |Sort Value)[0,-1].Value
# or
$min,$max = #($CustomObjects.Value |Sort)[0,-1]
Very succinct, easy to express - but might turn out to be slow on large collections
Obtaining min/max through keeping count is exactly what Measure-Object does:
$min,$max = [int]::MaxValue,[int]::MinValue
$CustomObjects |ForEach-Object {
$min = [Math]::Min($_.Value, $min)
$max = [Math]::Max($_.Value, $max)
}
Not as fancy, but faster for large collections

Answer 2

Mathias R. Jessen's helpful answer shows elegant - but potentially wasteful in terms of memory - solutions (Sort-Object of necessity needs to collect all input objects in memory so as to be able to determine the sort order).
Your own, Measure-Object-based approach takes advantage of the memory-throttling property of the pipeline.
Due to use of PowerShell's pipeline, both approaches are likely to be slow, however - see this answer for a discussion.
A simple optimization of your approach is to make the ForEach-Object value pipeline segment unnecessary by passing -Property value to Measure-Object:
$CustomObjects | Measure-Object -Property value -Minimum -Maximum
The Microsoft.PowerShell.Commands.GenericMeasureInfo returned by this command has .Minimum and .Maximum properties, so there's no strict reason to create separate $min and $max variables, but if you wanted to:
$measureResult = $CustomObjects | Measure-Object -Property value -Minimum -Maximum
$min, $max = $measureResult.Minimum, $measureResult.Maximum
If you'd rather not create an auxiliary variable, you can use the following, which uses the .ForEach() array method:
$min, $max = ($CustomObjects | Measure-Object -Property value -Minimum -Maximum).
ForEach({ $_.Minimum, $_.Maximum })