New-Variable

New-Variable [-Name*] <String> [[-Value] <Object>] [-Confirm] [-Description <String>] [-Force] [-Option {None |ReadOnly | Constant | Private | AllScope | Unspecified}] [-PassThru] [-Scope <String>] [-Visibility {Public |Private}] [-WhatIf] [<CommonParameters>]

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, 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

-Confirm [<SwitchParameter>]

Default value is False
Accepts pipeline input False

Prompts you for confirmation before running the cmdlet.

-Description <String>

Default value is None
Accepts pipeline input False

Specifies a description of the variable.

-Force [<SwitchParameter>]

Default value is False
Accepts pipeline input False

Indicates that the cmdlet creates a 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.

-Name <String>

This value is required
Default value is None
Accepts pipeline input ByPropertyName

Specifies a name for the new variable.

-Option <ScopedItemOptions>

Default value is None
Accepts pipeline input False

Specifies the value of the Options property of the variable.The acceptable values for this parameter are:

- None. Sets no options. (None is the default.) - ReadOnly. Can be deleted. Cannot be not changed, except by using the Force parameter. - Private. The variable is available only in the current scope. - AllScope. The variable is copied to any new scopes that are created. - Constant. Cannot be deleted or changed. Constant is valid only when you are creating a variable. You cannot change the options of an existing variable to Constant.

To see the Options property of all variables in the session, type `Get-Variable | Format-Table -Property name, options -autosize`.

-PassThru [<SwitchParameter>]

Default value is False
Accepts pipeline input False

Returns an object representing the item with which you are working. By default, this cmdlet does not generate any output.

-Scope <String>

Default value is None
Accepts pipeline input False

Specifies the scope of the new variable. The acceptable values for this parameter are:

- Global

- Local

- Script

- 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.

-Value <Object>

Default value is None
Accepts pipeline input ByPropertyName

Specifies the initial value of the variable.

-Visibility <SessionStateEntryVisibility>

Default value is None
Accepts pipeline input False

Determines whether the variable is visible outside of the session in which it was created. This parameter is designed for use in scripts and commands that will be delivered to other users. The acceptable values for this parameter 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, or in displays of the Variable: drive. Commands to read or change the value of a private variable return an error. However, the user can run commands that use a private variable if the commands were written in the session in which the variable was defined.

-WhatIf [<SwitchParameter>]

Default value is False
Accepts pipeline input False

Shows what would happen if the cmdlet runs. The cmdlet is not run.

<CommonParameters>

This cmdlet supports the common parameters: Verbose, Debug,ErrorAction, ErrorVariable, WarningAction, WarningVariable,OutBuffer, PipelineVariable, and OutVariable.

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 representing the new variable. Otherwise, this cmdlet does not generate any output.

Examples

Create a variable:
```
PS C:\> New-Variable days
```
This command creates a new variable named days. You are not required to type the Name parameter.
Create a variable and assign it a value:
```
PS C:\> New-Variable -Name "zipcode" -Value 98033
```
This command creates a variable named zipcode and assigns it the value 98033.
Create a variable with the ReadOnly option:
```
PS C:\> New-Variable -Name Max -Value 256 -Option ReadOnly
PS C:\> 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

PS C:\> New-Variable -Name max -Value 1024 -Force
```
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.

Create a private variable:

PS C:\> New-Variable -Name counter -Visibility private

   #Effect of private variable in a module.

PS C:\> Get-Variable c*

   Name                           Value
   ----                           -----
   Culture                        en-US
   ConsoleFileName
   ConfirmPreference              High
   CommandLineParameters          {} PS C:\>$counter
   "Cannot access the variable '$counter' because it is a private variable" PS C:\>Get-Counter
   Name         Value
   ----         -----
   Counter1     3.1415
   ...

This command demonstrates the behavior of a private variable in a module. The module contains the Get-Counter cmdlet, 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 change the value of the Counter variable, but the Counter variable can be read and changed by the commands in the module.

Additional Notes

This work is licensed under a Creative Commons Attribution 4.0 International. It is attributed to Microsoft Corporation and can be found here.

PowerShell Commands