Powershell - how do I edit an existing property in a custom object - powershell

Question

I looking for way how update noteproperty in existing psobject, for example I have system.array of psobjects ($a):
Group Assigment
----- ---------
Group1 Home
Group2 Office
Question is how update 'Home' to something other.
$a | gm:
TypeName: System.Management.Automation.PSCustomObject
Name MemberType Definition
---- ---------- ----------
Equals Method bool Equals(System.Object obj)
GetHashCode Method int GetHashCode()
GetType Method type GetType()
ToString Method string ToString()
Assigment NoteProperty System.String Assigment=Office
Group NoteProperty System.String Group=Group1
$a.GetType():
IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True Object[] System.Array
Thank you for future help.

Answer 1

It's not really clear what is your problem : select the good object or update it's value ?
$col=#()
$props=#{"group"="group1";"assignment"="home"}
$col += new-object pscustomobject -property $props
$props2=#{"group"="group2";"assignment"="office"}
$col += new-object pscustomobject -property $props2
#select object with home assignment
$rec=$col | where {$_.assignment -eq "home"}
#replace the value
$rec.assignment="elsewhere"
#display collection with updated value
$col

Answer 2

I don't think this works if $rec returns more than one record, though.
For example:
$rec = $col | where {$_.assignment -ne $null}
$rec.assignment = "elsewhere"
In theory that should set every individual record's assignment to "elsewhere" but it really just returns an error that the property "assignment" cannot be found on this object. I think for this to really work you'd need:
$recs = $col | where {$_.assignment -ne $null}
foreach ($r in $recs) {
$r.assignment="elsewhere"
}
Unless there's a way to set a value to every record in a given array, which I freely admit there may be.