Referenz und Spickzettel

main(_) ->
    io:format("~p~n", [erlang:system_info(otp_release) >= "20"]),
    io:format("~p~n", [is_pid(self())]),
    io:format("~p~n", [is_function(fun(X) -> X end)]),
    io:format("~p~n", [erlang:abs(-7)]),
    io:format("~p~n", [element(1, {a, b})]),
    io:format("~p~n", [is_list("abc")]),
    io:format("~p~n", [atom_to_list(hallo)]),
    io:format("~p~n", [list_to_atom("welt")]),
    io:format("~p~n", [length([])]),
    io:format("~p~n", [min(3, 9)]),
    io:format("~p~n", [rand:uniform(6) >= 1]),
    io:format("~p~n", [is_binary(<<1>>)]),
    io:format("~p~n", [erlang:process_info(self(), message_queue_len)]),
    io:format("~p~n", [timer:tc(fun() -> ok end) =/= error]),
    io:format("~p~n", [calendar:is_leap_year(2024)]),
    io:format("~p~n", [calendar:day_of_the_week(2024, 3, 15)]),
    io:format("~p~n", [filename:extension("a/b/c.txt")]),
    io:format("~p~n", [filename:join(["a", "b", "c.txt"])]),
    io:format("~p~n", [file:read_file("/nicht/da")]).

true
true
true
7
a
true
"hallo"
welt
0
3
true
true
{message_queue_len,0}
true
true
5
".txt"
"a/b/c.txt"
{error,enoent}

main(_) ->
    X = 1,
    X = 2.

no match of right hand side value 2

main(_) ->
    unbekannt:funktion().

undef