Declaring variable

• In PowerShell, variables begins with a dollar sign ($)
• Default value of a variable is $null
• Usage: variable name with $ -> $FullName = $FirstName + $LastName

$FooBarBaz = "foo-bar-baz"
$Path = "C:\Windows\System32"

$Today = (Get-Date).DateTime

Details: https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_variables

Data type of a variable

• PowerShell variables are loosely typed, which means that they aren’t limited to a particular type of object
• A single variable can even contain a collection, or array, of different types of objects at the same time

Delete variable

• To delete the value of a variable:
  • Clear-Variable -Name MyVariable (variable name without $)
  • or $MyVariable = $null
• To delete the variable
  • Remove-Variable -Name MyVariable
  • Remove-Item -Path Variable:\MyVariable

Variable scope

https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_scopes

Types of variable

Automatic Variable

https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_automatic_variables

Environment variable

https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_environment_variables