Set-Variable
SYNOPSIS
Sets the value of a variable. Creates the variable if one with the requested name does not exist.
SYNTAX
Set-Variable [-Name] <String[]> [[-Value] <Object>] [-Include <String[]>] [-Exclude <String[]>]
[-Description <String>] [-Option <ScopedItemOptions>] [-Force] [-Visibility <SessionStateEntryVisibility>]
[-PassThru] [-Scope <String>] [-WhatIf] [-Confirm] [<CommonParameters>]
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
Set-Variable -Name "desc" -Value "A description"
Get-Variable -Name "desc"
Name Value
---- -----
desc A description
Example 2: Set a global, read-only 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
PS C:\> New-Variable -Name "counter" -Visibility Public -Value 26
PS C:\> $Counter
26
PS C:\> Get-Variable c*
Name Value
---- -----
Culture en-US
ConsoleFileName
ConfirmPreference High
CommandLineParameters {}
Counter 26
PS C:\> Set-Variable -Name "counter" -Visibility Private
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:\> .\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
-Description
Specifies the description of the variable.
Type: System.String
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: None
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: System.String[]
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-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: System.Management.Automation.SwitchParameter
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: 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: System.String[]
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-Name
Specifies the variable name.
Type: System.String[]
Parameter Sets: (All)
Aliases:
Required: True
Position: 0
Default value: None
Accept pipeline input: True (ByPropertyName)
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: System.Management.Automation.ScopedItemOptions
Parameter Sets: (All)
Aliases:
Accepted values: None, ReadOnly, Constant, Private, AllScope, Unspecified
Required: False
Position: Named
Default value: None
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: System.Management.Automation.SwitchParameter
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: 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 (../Microsoft.PowerShell.Core/About/about_scopes.md).
Type: System.String
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: Local
Accept pipeline input: False
Accept wildcard characters: False
-Value
Specifies the value of the variable.
Type: System.Object
Parameter Sets: (All)
Aliases:
Required: False
Position: 1
Default value: None
Accept pipeline input: True (ByPropertyName, ByValue)
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: System.Management.Automation.SessionStateEntryVisibility
Parameter Sets: (All)
Aliases:
Accepted values: Public, Private
Required: False
Position: Named
Default value: Public
Accept pipeline input: False
Accept wildcard characters: False
-Confirm
Prompts you for confirmation before running the cmdlet.
Type: System.Management.Automation.SwitchParameter
Parameter Sets: (All)
Aliases: cf
Required: False
Position: Named
Default value: False
Accept pipeline input: False
Accept wildcard characters: False
-WhatIf
Shows what would happen if the cmdlet runs. The cmdlet is not run.
Type: System.Management.Automation.SwitchParameter
Parameter Sets: (All)
Aliases: wi
Required: False
Position: Named
Default value: False
Accept pipeline input: False
Accept wildcard characters: False
CommonParameters
This cmdlet supports the common parameters: -Debug, -ErrorAction, -ErrorVariable, -InformationAction, -InformationVariable, -OutVariable, -OutBuffer, -PipelineVariable, -Verbose, -WarningAction, and -WarningVariable. For more information, see about_CommonParameters.
INPUTS
System.Object
You can pipe an object that represents the value of the variable to `Set-Variable`.
OUTPUTS
None or System.Management.Automation.PSVariable
When you use the PassThru parameter, `Set-Variable` generates a System.Management.Automation.PSVariable object representing the new or changed variable. Otherwise, this cmdlet does not generate any output.