ColorConsole [Version 1.7.1000] PowerShell 2.0-Export
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.
C:\Windows-7>Powershell get-help about_Ref -full
# 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
C:\Windows>powershell
get-help about_regular_expressions -full
