Functions are one of the fundamental building blocks of Power Query. In addition to the native ones, we can create our own so that we don't have to write everything repeatedly. Custom functions can be one of your best friends for making your work easier in Power Query. But you need to be able to create them and set the input parameters, including whether they are mandatory or optional.

But once we create the function, it doesn't end there! To pass the function to someone or not forget what it does, it is good to know how to add documentation metadata that will be displayed in the preview of the function and used for quick understanding.

Start building custom functions and advance your Power Query capabilities.