Getting the Object Type in PowerShell

First post of the year and in a while and I would like to talk about the types of the objects in PowerShell.

Much like C#, each object has a type in PowerShell. This type is proven to be very helpful when developing functions and cmdlets since it provides information about the object we are dealing with.

For example you may have a variable that holds the value "1" but it can be of type string, integer, double and others. The way to differentiate is to examine the type of the variable.

There are may ways to get the type of a PowerShell object but first, let's get the newest event in the application log to use as example:

PS C:\> $obj = Get-EventLog -LogName Application -Newest 1

PS C:\> $obj

Index Time         EntryType   Source InstanceID Message
----- ----         ---------   ------ ---------- -------
3882  Jan 07 20:39 Information ESENT  916        svchost (3356,G,0) The beta ...

The first way to get the type of the object is to use the "GetType" method of the object. This method exists on all objects since it is inherited from the basic object type.

PS C:\> $obj.GetType()

IsPublic IsSerial Name  BaseType
-------- -------- ----  --------
True     True     Event LogEntry System.ComponentModel.Component

PS C:\> $obj.GetType().FullName
System.Diagnostics.EventLogEntry

Than name of the type will be in the "Name" property. Furthermore, the "FullName" property of the returning object will provide the full name of the type.

The second way is to use the Get-TypeData cmdlet like the following:

PS C:\> $obj | Get-TypeData

TypeName                                    Members
--------                                    -------
System.Diagnostics.EventLogEntry            {[EventID,System....}

The "TypeName" property will contain the full name of the type.

Last but not least, the good old "Get-Member" function will display the full name of the type:

PS C:\> $obj | Get-Member

TypeName: System.Diagnostics.EventLogEntry#Application/ESENT/916

Name MemberType Definition
---- ---------- ----------

You can always check TechNet and MSDN for an object type and see it's properties and methods!