About Ordered

OrderedDictionary is made available in PowerShell by using the [Ordered] keyword. This was introduced along with PSCustomObject in PowerShell 3.

An OrderedDictionary preserves the order in which keys were added. For example:

$ordered = [Ordered]@{
    One   = 1
    Two   = 2
    Three = 3
}

Viewing the value of $ordered will show the keys appear in the same order they were entered:

PS> $ordered
Name                           Value
----                           -----
One                            1
Two                            2
Three                          3

Conversely, a hashtable may show the keys in a different order:

PS> @{ One = 1; Two = 2; Three = 3 }
Name                           Value
----                           -----
Two                            2
Three                          3
One                            1

In PowerShell 7, a type accelerator exists for [Ordered], which makes the derivation of the type fairly...