Erlang更改列表中元素的值

Question

Hello is there a way to change the value of the head of a list in Erlang

 Hd -> store2(Key, N,[New|List],New,false)

this is as close I came to changing it New is the new element to the Head element of the list

store(Key, N, TupleList, New) when is_integer(N), N > 0, is_tuple(New) ->
store2(Key, N, TupleList, New, false).

store2(_Key,_N,[], New, false) -> [New];
  store2(Key, N,List, New, false) -> case fetch(Key, N, List) of
     [] -> List;
     false -> List++[New];
     Hd -> store2(Key, N,[New|List],New,false)
   end.

to clarify even further im using a function called fetch that I defined to find an element to replace with another element which is New

Answer 1

Just prepend your new head to the tail of List .

[New|tl(List)]

You usually write it as pattern matching

some_function(..., [_Old|Tail] = _List, ...)->
    ...
    NewList = [New|Tail],
    ...