I convert a decimal number to binary format:

A = integer_to_list(5, 2).

And I add to the list a list of zeros:

 A ++ [0, 0, 0, 0, 0].

I get [49, 48, 49, 0, 0, 0, 0, 0] . It is necessary at the union to get [1, 0, 1, 0, 0, 0, 0, 0] .

    2 answers 2

    The fact is that you get a list of characters "101", not numbers. Characters have a numeric representation, according to the ASCII table, and code 0 corresponds to code 48, and character 1, respectively, 49.

    Try to subtract the code of the digit 0 from each element of the array, obtained after calling the function integer_to_list(5, 2) .

    This can be done, for example, as follows:

     A = lists:map(fun(X) -> X-$0 end, integer_to_list(5, 2)).

      A bit more sane way:

       i2bl(I) when is_integer(I) -> i2bl(<<I>>, []). i2bl(<<>>, Acc) -> Acc; i2bl(<<B:1, Rest/bitstring>>, Acc) -> i2bl(Rest, [B|Acc]).

      Example of use:

       1> i2bl(5). [1,0,1,0,0,0,0,0]
      • And the clot with zero is not forgotten? - Dmitry Belyaev
      • @DmitryBelyaev And what is wrong with zero? - igor
      • I did not notice this, that there the variable B is bind. And the code to run was lazy. - Dmitry Belyaev