Question

I am working on Euler 8. After a bit of reading i decided that use of the map function would solve a problem for me. Throwing a simple test program together to make sure I understood the concepts came up short.

From within the shell.

1> List = {3, 1, 4}.
{3,1,4}

2> io:format("oh my ~w ~n", [List]).
oh my {3,1,4}
ok

3> lists:map(fun (Z) -> Z * Z end , List).
** exception error: no function clause matching
                    lists:map(#Fun<erl_eval.6.80247286>,{3,1,4})

I see the fun, and the list in the message.
What concept am I missing here?

Answer 1

your List is actually a tuple. {} is for tuples, [] is for lists.

your example should be:

1> List = [3,1,4].
[3,1,4]
2> lists:map(fun(Z) -> Z*Z end, List).
[9,1,16]