Strange behavior of rem in Elixir?

Question

I tried these two lines of simple Enum.drop_while ... seems easy enough but I don't understand why they turn up differently:

iex(6)> 1..100 |> Enum.drop_while(fn(x) -> rem(x,10) == 0 end) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, ...] iex(7)> 1..100 |> Enum.drop_while(fn(x) -> rem(10,x) == 0 end) [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, ...]

Appreciate some help.

Answer 1

rem x, 10

and

rem 10, x

is not the same thing. That's why you get different results.

See also:

iex>div 10, 1
10

iex> div 1, 10
0