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PowerShell: Advanced functions

A function becomes advanced if it contains a [cmdLetBinding()] param(…) statement:

function advanced-func {
   [cmdLetBinding()]
    param(
       …
    )

    … 

}

Advanced functions can have up to three script blocks: begin, process and end.

Differences from compiled cmdlets

Microsoft's documentation lists the following three differences between advanced functions and compiled cmdlets:

Advanced function parameter binding does not throw an exception when an array of strings is bound to a boolean parameter.
The ValidateSet attribute and the ValidatePattern attribute cannot pass named parameters.
Advanced functions cannot be used in transactions.

See also

The CmdLetBinding type accelerator