You may consider lists still beta, so the documentation is not quite there yet. Here is an article from a colleague, and in this example of a summary table I provided in another thread, I have comments in my code.
Basically, the syntax for most list functions is list.functionName((el, i) => output/condition) where “el” is the current element, and the optional argument “i” is the current index, which you might use to reference corresponding elements in other lists. You can use any variable name you like for “el” and “i”.