Powershell Define Powershell Objects

Use PsObject like this:

$o = new-Object PsObject -property @{Name='donald'; Kind='duck' }

You pass a hashtable as argument for -property parameter. Also you can create empty object and add properties later:

$o = New-Object PsObject$o | Add-Member NoteProperty project myproj.csproj$o | Add-Member NoteProperty Success $true

You can of course use pipe to Add-Member

$o = New-Object PsObject# ...$o |    Add-Member NoteProperty project myproj.csproj -pass |   Add-Member NoteProperty Success $true

If I understand the question, you're asking a couple things:

1. Can you explicitly specify the type of a variable?
2. What type does Powershell use if you don't specify one yourself?

Powershell will certainly let you specify a type explicitly, but it will also infer types. Note that since all types inherit from System.Object, explicitly specifying [object] in a combined declaration/assignment statement has no value that I can see. The type system will still infer an appropriate child type. For example:

$x = 3$x.GetType() # Returns 'Int32'Remove-Variable x[object] $x = 3$x.GetType() # Returns 'Int32'Remove-Variable x[valuetype] $x = 3$x.GetType() # Returns 'Int32'Remove-Variable x[int] $x = 3$x.GetType() # Returns 'Int32'

If you split up the declaration and assignment, you can create a variable of type Object:

Remove-Variable x$x = new-object -TypeName Object$x.GetType() # Returns 'Object'

...but once you assign a value, the variable gets a new inferred type anyway:

$x = 3$x.GetType() # Returns 'Int32'

While the type system will happily infer Int32 when you specify Object, explicit types win when the inferred type would be incompatible. For example:

$x = 3          # Gets inferred type 'Int32'[string] $x = 3 # Gets explicit type 'String'$x = 'x'        # Gets inferred type 'String'[char] $x = 'x' # Gets explicit type 'Char'

If your question is more geared toward defining and using custom object types, Stej's answer is excellent.

Since Powershell 3 one can also parse HashTables to Custom Objects like:

[PSObject] $Piza = [PSCustomObject] @{    Ingredients = 4}

Or if you like to define more detailed types in your object you could use the -AsCustomObject Parameter from New-Module

[PSObject] $Piza = New-Module -AsCustomObject -ScriptBlock {    [Guid]$id = [Guid]::NewGuid()    [String] $Name = 'Macaroni'     Function TestFunction() {}    # Dont forget to export your members and functions     # as this is built up as a module and stuffed into     # an object later    Export-ModuleMember -Function * -Variable *}

As there are no things as classes in posh you can add custom classnames and namespaces to your object that you can query later (pseudo instance ;)

$Piza.PSObject.TypeNames.Insert(0, 'Pizas.Macaroni')