The WhatIfPreference variable holds a Boolean value (true or false) and has a default value of false.

If the preference variable is set to true, all commands that support WhatIf will act as if the parameter is explicitly set. A new value may be set for the variable, as shown in the following code:

$WhatIfPreference = $true 

The WhatIf preference variable takes precedence over the Confirm parameter. For example, the WhatIf dialog will be shown when running the following New-Item, but the Confirm prompt will not:

$WhatIfPreference = $true 
New-Item NewFile.txt -Confirm