Custom Objects

Functions should output objects, and [pscustomobject] is the simplest way to create them.

$server = [pscustomobject]@{
  Name     = 'web01'
  Role     = 'Web'
  MemoryGB = 16
  Online   = $true
}

$server
$server.Role
$server.MemoryGB = 32
$server | Add-Member -NotePropertyName Location -NotePropertyValue 'London'
$server.Location

Name  Role MemoryGB Online
----  ---- -------- ------
web01 Web        16   True
Web
London

• Properties keep the order you wrote them in.
• Change properties by assignment; add new ones with Add-Member.

Collections of objects

Output one object per item from a loop, and you get a table-ready, sortable collection:

$inventory = foreach ($line in 'web01,16,Web', 'db01,64,Database', 'web02,16,Web') {
  $name, $memory, $role = $line -split ','
  [pscustomobject]@{
    Name     = $name
    MemoryGB = [int]$memory
    Role     = $role
  }
}

$inventory | Sort-Object MemoryGB -Descending | Format-Table
($inventory | Measure-Object MemoryGB -Sum).Sum

Name  MemoryGB Role
----  -------- ----
db01        64 Database
web01       16 Web
web02       16 Web

96

$name, $memory, $role = ... assigns the three parts of the split to three variables at once.

Objects vs hash tables

Common mistakes

• Outputting strings like "web01 has 16 GB" from functions. It reads nicely but can't be sorted, filtered, or exported. Output an object and let the caller decide how to display it.