Summing an array of Objects in Powershell - powershell

Question

I have an array of objects that are holding integer values.
$row = new-Object PSObject # create a new object to hold its data
$row | Add-Member -Name "sheet_number" -MemberType NoteProperty -Value 1
$row | Add-Member -Name "frame_number" -MemberType NoteProperty -Value 2
$row | Add-Member -Name "sheet_height" -MemberType NoteProperty -Value 1200
$row | Add-Member -Name "frame_height" -MemberType NoteProperty -Value 1200
$row | Add-Member -Name "frame_width" -MemberType NoteProperty -Value 3300
$row | Add-Member -Name "orientation" -MemberType NoteProperty -Value 0
$frames += $row
this is in a for loop intended to iterate through several times. But the sheet_number property should only have a couple values. what I need is to sum up the values in frame_width where the sheet_number is the same.
Pseudo Code:
sheet_width = sum of frame_width where sheet number = 1

Answer 1

Use a combination of Where-Object, ForEach-Object, and Measure-Object:
$sum = (
$frames |
Where-Object sheet_number -eq 1 |
ForEach-Object frame_width |
Measure-Object -Sum
).Sum
To do it for all sheet numbers, additionally use Group-Object:
$arrayOfSums =
$frames |
Group-Object sheet_number |
ForEach-Object {
($_.Group.frame_width | Measure-Object -Sum).Sum
}