PowerShell includes a variable provider that can be queried as a filesystem using Get-ChildItem, Test-Path, and so on.

Get-ChildItem may be used to list all of the variables in the current scope by running the command shown as follows:

Get-ChildItem variable:

The output will include the default variables, as well as any variables created by modules that might have been imported.

As this behaves much like a filesystem, Test-Path may be used to determine whether or not a variable exists:

Test-Path variable:VerbosePreference

Set-Item may be used to change the value of a variable or create a new variable:

Set-Item variable:
ew -Value variable

Get-Content can also be used to retrieve the content of a variable:

Get-Content variable:OutputEncoding

The backslash character used in the preceding examples is optional. The output from each command in the following example will be identical:

$new = 123
Get-Item variable:
ew
Get-Item variable:new