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Description

The Set-Variable cmdlet assigns a value to a specified variable or changes the current value. If the variable does not exist, the cmdlet creates it.

Examples

Example 1: Set a variable and get its value

These commands set the value of the $desc variable to A description , and then gets the value of the variable.

Set-Variable -Name "desc" -Value "A description"
Get-Variable -Name "desc"
Name                           Value
----                           -----
desc                           A description

Example 2: Set a global, read-only variable

This example creates a global, read-only variable that contains all processes on the system, and then it displays all properties of the variable.

Set-Variable -Name "processes" -Value (Get-Process) -Option constant -Scope global -Description "All processes" -PassThru |
    Format-List -Property *

The command uses the Set-Variable cmdlet to create the variable. It uses the PassThru parameter to create an object representing the new variable, and it uses the pipeline operator ( | ) to pass the object to the Format-List cmdlet. It uses the Property parameter of Format-List with a value of all ( * ) to display all properties of the newly created variable.

The value, (Get-Process) , is enclosed in parentheses to ensure that it is executed before being stored in the variable. Otherwise, the variable contains the words Get-Process .

Example 3: Understand public vs. private variables

This example shows how to change the visibility of a variable to Private . This variable can be read and changed by scripts with the required permissions, but it is not visible to the user.

New-Variable -Name "counter" -Visibility Public -Value 26
$Counter
Get-Variable c*
Name                  Value
----                  -----
Culture               en-US
ConsoleFileName
ConfirmPreference     High
CommandLineParameters {}
Counter               26
Set-Variable -Name "counter" -Visibility Private
Get-Variable c*
Name                  Value
----                  -----
Culture               en-US
ConsoleFileName
ConfirmPreference     High
CommandLineParameters {}
$counter
"Cannot access the variable '$counter' because it is a private variable"
.\use-counter.ps1
#Commands completed successfully.

This command shows how to change the visibility of a variable to Private. This variable can be read and changed by scripts with the required permissions, but it is not visible to the user.

Parameters

-Confirm

Prompts you for confirmation before running the cmdlet.

Type: SwitchParameter Aliases:cf Position:Named Default value:False Required:False Accept pipeline input:False Accept wildcard characters:False

-Description

Specifies the description of the variable.

Type: String Position:Named Default value:None Required:False Accept pipeline input:False Accept wildcard characters:False

-Exclude

Specifies an array of items that this cmdlet excludes from the operation. The value of this parameter qualifies the Path parameter. Enter a path element or pattern, such as *.txt . Wildcards are permitted.

Type: String [ ] Position:Named Default value:None Required:False Accept pipeline input:False Accept wildcard characters:True

-Force

Allows you to create a variable with the same name as an existing read-only variable, or to change the value of a read-only variable.

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

Type: SwitchParameter Position:Named Default value:False Required:False Accept pipeline input:False Accept wildcard characters:False

-Include

Specifies an array of items that this cmdlet includes in the operation. The value of this parameter qualifies the Name parameter. Enter a name or name pattern, such as c* . Wildcards are permitted.

Type: String [ ] Position:Named Default value:None Required:False Accept pipeline input:False Accept wildcard characters:True

-Name

Specifies the variable name.

Type: String [ ] Position:0 Default value:None Required:True Accept pipeline input:True Accept wildcard characters:False

-Option

Specifies the value of the Options property of the variable.

Valid values are:

  • None : Sets no options. ( None is the default.)
  • ReadOnly : Can be deleted. Cannot be changed, except by using the Force parameter.
  • 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 .
  • Private : The variable is available only in the current scope.
  • AllScope : The variable is copied to any new scopes that are created.
  • These values are defined as a flag-based enumeration. You can combine multiple values together to set multiple flags using this parameter. The values can be passed to the Option parameter as an array of values or as a comma-separated string of those values. The cmdlet will combine the values using a binary-OR operation. Passing values as an array is the simplest option and also allows you to use tab-completion on the values.

    Type: ScopedItemOptions Accepted values:None, ReadOnly, Constant, Private, AllScope, Unspecified Position:Named Default value:None Required:False 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.

    Type: SwitchParameter Position:Named Default value:False Required:False Accept pipeline input:False Accept wildcard characters:False

    -Scope

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

  • Global
  • Local
  • Script
  • Private
  • 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 .

    Type: String Position:Named Default value:Local Required:False Accept pipeline input:False Accept wildcard characters:False

    -Value

    Specifies the value of the variable.

    Type: Object Position:1 Default value:None Required:False Accept pipeline input:True Accept wildcard characters:False

    -Visibility

    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.

    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 , 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.

    Type: SessionStateEntryVisibility Accepted values:Public, Private Position:Named Default value:Public Required:False Accept pipeline input:False Accept wildcard characters:False

    -WhatIf

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

    Type: SwitchParameter Aliases:wi Position:Named Default value:False Required:False Accept pipeline input:False Accept wildcard characters:False

    Inputs

    Object

    You can pipe an object representing the value of the variable to this cmdlet.

    Outputs

    By default, this cmdlet returns no output.

    PSVariable

    When you use the PassThru parameter, this cmdlet returns a PSVariable object representing the new or changed variable.

    Notes

    PowerShell includes the following aliases for Set-Variable :

  • All platforms:
  •