use of "LEFT() or RIGHT()" type functions in Query Editor / Custom Column

[Anonymous]

I'm trying to add a column in the query editor by using an if-then statement based on the left x characters of one of the other columns in my table. When I use a nested if statement in the table itself and add the custom field, this seems to work using yet this does not seem to work when adding a custom column in the query editor environment. Here's what I've tried:

if left(column,5)="abcde" then "a" else "b"

I realise I could work with adding the column outside the query editor, but I'd like to understand how to use the function inside it as well. 

thanks

[PattemManohar · Accepted solution]

@Anonymous  Functions in DAX and M-Language (Power Query) are different.

You need to use as below in Power Query Editor as custom column

if Text.Start(column,5) = "abcde" then "a" else "b" 

if Text.End(column,2) = "de" then "d" else "e"