about_Ref

TOPIC
	about_Ref

SHORT DESCRIPTION
	Describes how to create and use a reference variable type.

LONG DESCRIPTION
	You can use the reference variable type to permit a method to change the
	value of a variable that is passed to it. 

	When the [ref] type is associated with an object, it returns a reference
	to that object. If the reference is used with a method, the method can
	refer to the object that was passed to it. If the object is changed within
	the method, the change appears as a change in the value of the variable
	when control returns to the calling method. 

	To use referencing, the parameter must be a reference variable. If it is
	not, an InvalidArgument exception is thrown.

	The parameters used in method invocations must match the type required 
	by the methods.  

	Examples:

		PS> function swap([ref]$a,[ref]$b) 
		>> { 
		>>  $a.value,$b.value = $b.value,$a.value 
		>> }

		PS> $a = 1
		PS> $b = 10
		PS> $a,$b
		1
		10
		PS> swap ([ref]$a) ([ref]$b)
		PS> $a,$b
		10
		1

		PS C:\ps-test> function double
		>> {
		>>  param ([ref]$x) $x.value = $x.value * 2
		>> }

		PS C:> $number = 8
		PS C:> $number
		8
		PS C> double ([ref]$number)
		PS C> $number
		16

		The variable must be a reference variable.

		PS C:\ps-test> double $number
		double : Reference type is expected in argument.
		At line:1 char:7
		+ double  <<<< $number

 
SEE ALSO
	about_Variables
	about_Environment_Variables
	about_Functions
	about_Script_Blocks