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Tutorials  PowerShell Cmdlet Help for New-Variable



NAME
New-Variable

SYNOPSIS
Creates a new variable.

SYNTAX
New-Variable [-Name] [[-Value] ] [-Description ] [-Force] [-Option {None | ReadOnly | Cons
tant | Private | AllScope}] [-PassThru] [-Scope ] [-Visibility {Public | Private}] [-Confirm] [-WhatIf] [ ommonParameters>]


DESCRIPTION
The New-Variable cmdlet creates a new variable in Windows PowerShell. You can assign a value to the variable while
creating it or assign or change the value after it is created.

You can use the parameters of New-Variable to set the properties of the variable (such as those that create read-on
ly or constant variables), set the scope of a variable, and determine whether variables are public or private.

Typically, you create a new variable by typing the variable name and its value, such as "$var = 3", but you can use
the New-Variable cmdlet to use its parameters.


PARAMETERS
-Description
Specifies a description of the variable.

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

-Force []
Allows you to create a new variable with the same name as an existing read-only variable.

By default, you can overwrite a variable unless the variable has an option value of ReadOnly or Constant. For m
ore information, see the Option parameter.

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

-Name
Specifies a name for the new variable.

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

-Option
Sets the value of the Options property of the new variable.

Valid values are:

-- None: Sets no options. ("None" is the default.)

-- ReadOnly: The value of the variable cannot be changed except by using the Force parameter. You can use Remov
e-Variable to delete the variable.

-- Constant: The variable cannot be deleted, and its properties cannot be changed. "Constant" is available only
when you are creating an alias. You cannot change the option of an existing variable to "Constant".

-- Private: The variable is available only within the scope specified by the Scope parameter. It is inherited b
y child scopes. (This value is not related to the "Private" value of the Visibility parameter.)

-- AllScope: The variable is copied to any new scopes that are created.

To see the Options property of the variables, type "get-variable| format-table -property name, options -autosiz
e".

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

-PassThru []
Returns an object representing the new 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
Determines the scope of the new variable. 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). "Loca
l" is the default. For more information, see about_Scopes.

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

-Value
Specifies the initial value of the variable.

Required? false
Position? 2
Default value
Accept pipeline input? true (ByValue, ByPropertyName)
Accept wildcard characters? false

-Visibility
Determines whether the variable is visible outside of the session in which it was created. This parameter is de
signed for use in scripts and commands that will be delivered to other users.

Valid values are:

-- Public: The variable is visible. ("Public" is the default.)
-- Private: The variable is not visible.

When a variable is private, it does not appear in lists of variables, such as those returned by Get-Variable, o
r in displays of the Variable: drive. Commands to read or change the value of a private variable return an erro
r. However, the user can run commands that use a private variable if the commands were written in the session i
n which the variable was defined.

Required? false
Position? named
Default value Public
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
System.Object
You can pipe a value to New-Variable.


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


NOTES





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

C:\PS>new-variable days


Description
-----------
This command creates a new variable named "days". It has no value immediately following the command.





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

C:\PS>new-variable zipcode -value 98033


Description
-----------
This command creates a variable named "zipcode" and assigns it the value "98033".





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

C:\PS>new-variable -name max -value 256 -option readonly

new-variable -name max -value 1024

new-variable -name max -value 1024 -force

C:\PS> new-variable -name max -value 256 -option readonly

C:\PS> new-variable -name max -value 1024
New-Variable : A variable with name 'max' already exists.
At line:1 char:13
+ new-variable <<<< -name max -value 1024

C:\PS> new-variable -name max -value 1024 -force


Description
-----------
This example shows how to use the ReadOnly option of New-Variable to protect a variable from being overwritten.

The first command creates a new variable named Max and sets its value to "256". It uses the Option parameter with a
value of ReadOnly.

The second command tries to create a second variable with the same name. This command returns an error, because the
read-only option is set on the variable.

The third command uses the Force parameter to override the read-only protection on the variable. In this case, the
command to create a new variable with the same name succeeds.





-------------------------- EXAMPLE 4 --------------------------

C:\PS>new-variable -name counter -visibility private

#Effect of private variable in a module.

C:\PS> get-variable c*

Name Value
---- -----
Culture en-US
ConsoleFileName
ConfirmPreference High
CommandLineParameters {}

C:\PS> $counter
"Cannot access the variable '$counter' because it is a private variable"

C:\PS> Get-Counter
Name Value
---- -----
Counter1 3.1415
...


Description
-----------
This command demonstrates the behavior of a private variable in a module. The module contains the Get-Counter cmdle
t, which has a private variable named "Counter". The command uses the Visibility parameter with a value of "Private
" to create the variable.

The sample output shows the behavior of a private variable. The user who has loaded the module cannot view or chang
e the value of the Counter variable, but the Counter variable can be read and changed by the commands in the module
.






RELATED LINKS
Online version: http://go.microsoft.com/fwlink/?LinkID=113361
Get-Variable
Set-Variable
Remove-Variable
Clear-Variable