Power query code and use of the hash

Hi,
I've been trying to understand M code ( a bit ), and have found if i rename a step, when it is first referred to in the new step it doesn't need a # or quote marks.

Table.AddColumn(NoHash, "ColumName", each List.FirstN(#"NoHash"[Number],4))

or;

Table.AddColumn( EnterInFormBar, "NewColumn", each List.Sum(List.FirstN(#"EnterInFormBar"[Number],[Index])))

but when the name follows a functiion it does need the hash and double quotes.
I'd just like to know why one does need # and quotes and the other doesn't.

I've attached the table I've been playing around with. Any explanations or advice /help / book or website recommendations much appreciated.


Richard.

Neither of those require the hash and quotes since they don't contain spaces or other special characters.

Hi Rory,
So to be clear, are you saying the # is only necessary when there are spaces, and has nothing to do with indicating a previous step. ?

I don't think this correct, I have just tried removing the has form

Table.AddColumn(NoHash, "FirstFour", each List.FirstN(#"NoHash"[Number],4))

Thus

Table.AddColumn(NoHash, "FirstFour", each List.FirstN("NoHash"[Number],4))

and it now returns an error.

Richard.

Remove the quotes too:

Table.AddColumn(NoHash, "FirstFour", each List.FirstN(NoHash[Number],4))

Similar principle, yes. It's not just spaces - other special items like keywords and operators need the same treatment.