about_Type_Operators

TOPIC
	about_Type_Operators

SHORT DESCRIPTION
	Describes the operators that work with Microsoft .NET Framework types.

LONG DESCRIPTION
	The Boolean type operators (-is and -isnot) tell whether an object is an
	instance of a specified .NET Framework type. The -is operator returns a 
	value of TRUE if the type matches and a value of FALSE otherwise. 
	The -isnot operator returns a value of FALSE if the type 
	matches and a value of TRUE otherwise.
 

	The -as operator tries to convert the input object to the specified .NET 
	Framework type. If it succeeds, it returns the converted object. It if
	fails, it returns nothing. It does not return an error.


	The following table lists the type operators in Windows PowerShell.


	Operator  Description				 Example  
	--------  ------------------------	-------------------------------------
	-is	 Returns TRUE when the	 C:\PS> (get-date) -is [datetime]
			input is an instance		True
			of the specified
			.NET Framework type.

	-isnot	Returns TRUE when the	 C:\PS> (get-date) -isnot [datetime]
			input is not an instance	False
			of the specified
			.NETFramework type.
 
	-as	 Converts the input to	 C:\PS> 12/31/07 -as [datetime]
			the specified			 Monday, December 31, 2007 12:00:00 AM
			.NET Framework type.


	The syntax of the type operators is as follows:

		<input> <operator> [.NET type]

	You can also use the following syntax:

		<input> <operator> ".NET type"
 

	To specify the .NET Framework type, enclose the type name in 
	brackets ([ ]), or enter the type as a string, such as [DateTime] or 
	"datetime" for System.DateTime. If the type is not at the root of the 
	system namespace, specify the full name of the object type. You can omit
	"System.". For example, to specify System.Diagnostics.Process, enter
	[System.Diagnostics.Process], [Diagnostics.Process], or 
	"diagnostics.process". 

	The type operators always return a Boolean value, even if the input is a
	collection of objects. However, when the input is a collection, the type 
	operators match the .NET Framework type of the collection. They do not 
	match the type of each object, even when all of the objects are of the 
	same type.

	To find the .NET Framework type of an object, use the Get-Member cmdlet. 
	Or, use the GetType method of all the objects together with the FullName 
	property of this method. For example, the following statement gets the
	type of the return value of a Get-Culture command:

		C:\PS> (get-culture).gettype().fullname
		System.Globalization.CultureInfo
 

EXAMPLES
	The following examples show some uses of the Type operators:

		C:\PS> 32 -is [Float]
		False

		C:\PS> 32 -is "int"
		True

		C:\PS> (get-date) -is [DateTime]
		True

		C:\PS> "12/31/2007" -is [DateTime]
		False

		C:\PS> "12/31/2007" -is [String]
		True

		C:\PS> (get-process powershell)[0] -is [System.Diagnostics.Process]
		True

		C:\PS> (get-command get-member) -is [System.Management.Automation.CmdletInfo]
		True
 

	The following example shows that when the input is a collection of objects,
	the matching type is the .NET Framework type of the collection, not the type
	of the individual objects in the collection.

	In this example, although both the Get-Culture and Get-UICulture cmdlets 
	return System.Globalization.CultureInfo objects, a collection of these 
	objects is a System.Object array.

		C:\PS> (get-culture) -is [System.Globalization.CultureInfo]
		True

		C:\PS> (get-uiculture) -is [System.Globalization.CultureInfo]
		True

		C:\PS> (get-culture), (get-uiculture) -is [System.Globalization.CultureInfo]
		False

		C:\PS> (get-culture), (get-uiculture) -is [Array]
		True
 
		C:\PS> (get-culture), (get-uiculture) | foreach {$_ -is [System.Globalization.CultureInfo])
		True
		True

		C:\PS> (get-culture), (get-uiculture) -is [Object]
		True
 

	The following examples show how to use the -as operator.

		C:\PS> "12/31/07" -is [datetime]
		False

		C:\PS> "12/31/07" -as [datetime]
		Monday, December 31, 2007 12:00:00 AM

		C:\PS> $date = "12/31/07" -as [datetime]

		C:\PS>$a -is [datetime]
		True

		C:\PS> 1031 -as [System.Globalization.CultureInfo]

		LCID			 Name			 DisplayName
		----			 ----			 -----------
		1031			 de-DE			German (Germany)
	

	The following example shows that when the -as operator cannot convert the
	input object to the .NET Framework type, it returns nothing.


		C:\PS> 1031 -as [System.Diagnostic.Process]
		C:\PS>
 

SEE ALSO
	about_Operators