在列表Erlang中查找字段的位置

Question

I have this list

[id,container,feed_id,prev,next,feeds,name,street,street_no,
 firstname,lastname,email,password,phone...]

and I want to get the position of various elements, like name, which would be 7.

How do I get the position of elements in a list with Erlang?

lists:member(name, List).

This only returns whether an element is part of the list.

Answer 1

If it's likely that you want to look up the index for several items, or even all, and perhaps also do this repeatedly, it would be best to create an index mapping:

Map = maps:from_list(lists:zip(List, lists:seq(1, length(List))))

You can then keep this map around, and use it like this:

Pos = maps:get(Element, Map)