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Tutorials  PowerShell Cmdlet Help for Clear-Variable



NAME
Clear-Variable

SYNOPSIS
Deletes the value of a variable.

SYNTAX
Clear-Variable [-Name] [-Exclude ] [-Force] [-Include ] [-PassThru] [-Scope
] [-Confirm] [-WhatIf] []


DESCRIPTION
The Clear-Variable cmdlet deletes the data stored in a variable, but it does not delete the variable. As a result,
the value of the variable is NULL (empty). If the variable has a specified data or object type, Clear-Variable pres
erves the type of the object stored in the variable.


PARAMETERS
-Exclude
Omits the specified items. The value of this parameter qualifies the Name parameter. Enter a name element or pa
ttern, such as "s*". Wildcards are permitted.

Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false

-Force []
Allows the cmdlet to clear a variable even if it is read-only. Even using the Force parameter, the cmdlet canno
t clear constants.

Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false

-Include
Clears only the specified items. The value of this parameter qualifies the Name parameter. Enter a name element
or pattern, such as "s*". Wildcards are permitted.

Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false

-Name
Specifies the name of the variable to be cleared. Wildcards are permitted. This parameter is required, but the
parameter name ("Name") is optional.

Required? true
Position? 1
Default value
Accept pipeline input? true (ByPropertyName)
Accept wildcard characters? false

-PassThru []
Returns an object representing the cleared variable. By default, this cmdlet does not generate any output.

Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false

-Scope
Specifies the scope in which this alias is valid. Valid values are "Global", "Local", or "Script", or a number
relative to the current scope (0 through the number of scopes, where 0 is the current scope and 1 is its parent
). "Local" is the default. For more information, see about_Scopes.

Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false

-Confirm []
Prompts you for confirmation before executing the command.

Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false

-WhatIf []
Describes what would happen if you executed the command without actually executing the command.

Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false


This cmdlet supports the common parameters: Verbose, Debug,
ErrorAction, ErrorVariable, WarningAction, WarningVariable,
OutBuffer and OutVariable. For more information, type,
"get-help about_commonparameters".

INPUTS
None
You cannot pipe objects to Clear-Variable.


OUTPUTS
None or System.Management.Automation.PSVariable
When you use the PassThru parameter, Clear-Variable generates a System.Management.Automation.PSVariable object
representing the cleared variable. Otherwise, this cmdlet does not generate any output.


NOTES


To delete a variable, along with its value, use Remove-Variable or Remove-Item.

Clear-Variable will not delete the values of variables that are set as constants or owned by the system, even i
f you use the -Force parameter.

If the variable that you are clearing does not exist, the cmdlet has no effect. It does not create a variable w
ith a null value.

You can also refer to Clear-Variable by its built-in alias, "clv". For more information, see about_Aliases.


-------------------------- EXAMPLE 1 --------------------------

C:\PS>clear-variable my* -global


Description
-----------
This command deletes the value of the global variables that begin with "my".





-------------------------- EXAMPLE 2 --------------------------

C:\PS>$a=3

C:\PS>&{ clear-variable a }

C:\PS>$a
3


Description
-----------
These commands demonstrate that clearing a variable in a child scope does not clear the value in the parent scope.
The first command sets the value of the variable $a to "3". The second command uses the invoke operator (&) to run
a Clear-Variable command in a new scope. The variable is cleared in the child scope (although it did not exist), bu
t it is not cleared in the local scope. The third command, which gets the value of $a, shows that the value "3" is
unaffected.





-------------------------- EXAMPLE 3 --------------------------

C:\PS>clear-variable -name processes


Description
-----------
This command deletes the value of the $processes variable. The $processes variable still exists, but the value is n
ull.






RELATED LINKS
Online version: http://go.microsoft.com/fwlink/?LinkID=113285
Get-Variable
Set-Variable
New-Variable
Remove-Variable