Set-Variable is a Windows PowerShell command that allows users to create, change, and delete variables in the Windows PowerShell environment. This command is especially useful for automating tasks, as it allows users to store values in variables that can be used in subsequent commands. In this article, we’ll look at the syntax, parameters, inputs, outputs, examples, and tips for using the Set-Variable command.
Syntax
The syntax for the Set-Variable command is as follows:
Set-Variable [-Name] <String> [-Value] <Object> [-Option <SetVariableOption>] [-Description <String>] [-Force] [-PassThru] [-Scope <String>] [-WhatIf] [-Confirm] [-Verbose] [-ErrorAction <ActionPreference>] [-WarningAction <ActionPreference>] [-ErrorVariable <String>] [-WarningVariable <String>] [-OutVariable <String>] [-OutBuffer <Int32>]
Parameters
The Set-Variable command has several parameters that can be used to customize the command’s behavior. The table below lists the parameters and their descriptions.
| Parameter | Description |
|---|---|
| Name | The name of the variable to be created, changed, or deleted. |
| Value | The value of the variable to be created, changed, or deleted. |
| Option | The option for the variable to be created, changed, or deleted. Options include ReadOnly, Constant, Private, and Public. |
| Description | A description of the variable to be created, changed, or deleted. |
| Force | If specified, the command will overwrite existing variables without prompting. |
| PassThru | If specified, the command will return the variable object. |
| Scope | The scope of the variable to be created, changed, or deleted. Options include Global, Local, Script, and Private. |
| WhatIf | If specified, the command will simulate the action without actually performing it. |
| Confirm | If specified, the command will prompt the user to confirm the action. |
| Verbose | If specified, the command will output detailed information about the action. |
| ErrorAction | The action to be taken if an error is encountered. Options include Continue, Ignore, Inquire, SilentlyContinue, and Stop. |
| WarningAction | The action to be taken if a warning is encountered. Options include Continue, Ignore, Inquire, SilentlyContinue, and Stop. |
| ErrorVariable | The name of the variable to which any errors encountered will be assigned. |
| WarningVariable | The name of the variable to which any warnings encountered will be assigned. |
| OutVariable | The name of the variable to which the output of the command will be assigned. |
| OutBuffer | The number of objects to be stored in the output buffer before writing to the output variable. |
Inputs
The Set-Variable command accepts the following inputs:
- Name: The name of the variable to be created, changed, or deleted.
- Value: The value of the variable to be created, changed, or deleted.
- Option: The option for the variable to be created, changed, or deleted. Options include ReadOnly, Constant, Private, and Public.
- Description: A description of the variable to be created, changed, or deleted.
- Force: If specified, the command will overwrite existing variables without prompting.
- PassThru: If specified, the command will return the variable object.
- Scope: The scope of the variable to be created, changed, or deleted. Options include Global, Local, Script, and Private.
- WhatIf: If specified, the command will simulate the action without actually performing it.
- Confirm: If specified, the command will prompt the user to confirm the action.
- Verbose: If specified, the command will output detailed information about the action.
- ErrorAction: The action to be taken if an error is encountered. Options include Continue, Ignore, Inquire, SilentlyContinue, and Stop.
- WarningAction: The action to be taken if a warning is encountered. Options include Continue, Ignore, Inquire, SilentlyContinue, and Stop.
- ErrorVariable: The name of the variable to which any errors encountered will be assigned.
- WarningVariable: The name of the variable to which any warnings encountered will be assigned.
- OutVariable: The name of the variable to which the output of the command will be assigned.
- OutBuffer: The number of objects to be stored in the output buffer before writing to the output variable.
Outputs
The Set-Variable command has the following outputs:
- Variable object: If the PassThru parameter is specified, the command will return the variable object.
- Error object: If an error is encountered, the command will return an error object.
- Warning object: If a warning is encountered, the command will return a warning object.
- Output object: If the OutVariable parameter is specified, the command will return the output object.
Examples
The following examples demonstrate how to use the Set-Variable command:
- To create a new variable named “MyVar” with a value of “Hello World”, use the following command: Set-Variable -Name “MyVar” -Value “Hello World”
- To change the value of an existing variable named “MyVar” to “Goodbye World”, use the following command: Set-Variable -Name “MyVar” -Value “Goodbye World”
- To delete an existing variable named “MyVar”, use the following command: Set-Variable -Name “MyVar” -Value $null
- To create a new read-only variable named “MyVar” with a value of “Hello World”, use the following command: Set-Variable -Name “MyVar” -Value “Hello World” -Option ReadOnly
- To create a new variable named “MyVar” with a value of “Hello World” and a description of “This is my variable”, use the following command: Set-Variable -Name “MyVar” -Value “Hello World” -Description “This is my variable”