The CmdletBinding attribute

The CmdletBinding attribute is used to turn a function into an advanced function and is placed immediately above a param block. The attribute is used to add extra functionality, such as access to common parameters, control over the impact level, and so on. Scripts are not referred to as advanced scripts, but the same principle applies.

CmdletBinding may be used to do the following:

• Add common parameters, such as ErrorAction, Verbose, Debug, ErrorVariable, WarningVariable, and so on.
• Enable the use of the built-in $PSCmdlet variable.
• Declare support for WhatIf and Confirm and define the impact level of the command.

If a script or function has no parameters and wishes to make use of the capabilities provided by CmdletBinding, an empty param block must be declared:

function Test-EmptyParam {
    [CmdletBinding()]
    param ( )
}

One of the most important features added by CmdletBinding is the common parameters.

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