Result = string:join(Fruit, ", "),

-module(joinwords).
-export([start/0]).

start() ->

Fruit = ["Apple", "Carrot", "Banana"],

Result = string:join(Fruit, ", "),

io:format("~s~n", [Result]).

% In Erlang atoms tend to be preferred over strings. Problem could have, instead, used list of atoms together
% with suitable conversion:
%
% Fruit = ['Apple', 'Carrot', 'Banana'],
% Result = string:join(lists:map(fun (X) -> atom_to_list(X) end, Fruit), ", "),

Result = lists:foldl(fun (E, Acc) -> Acc ++ ", " ++ E end, hd(Fruit), tl(Fruit)),

-module(joinwords).
-export([start/0]).

start() ->

Fruit = ["Apple", "Banana", "Carrot"],

Result = lists:foldl(fun (E, Acc) -> Acc ++ ", " ++ E end, hd(Fruit), tl(Fruit)),

io:format("~s~n", [Result]).

Result = lists:flatten([ hd(Fruit) | [ ", " ++ X || X <- tl(Fruit)]]).

-module(joinwords).
-export([start/0]).

start() ->

Fruit = ["Apple", "Banana", "Carrot"],

Result = lists:flatten([ hd(Fruit) | [ ", " ++ X || X <- tl(Fruit)]]).

io:format("~s~n", [Result]).