# creating a binary number

Richard O'Keefe raoknz@REDACTED
Fri Dec 10 06:14:52 CET 2021

```What do you mean by "a binary number"?
Integers are just integers.  How they are represented
internally is none of our business; how they are
represented externally is up to you.

2#0
2#1
2#10
2#11
2#100
2#101
2#110
2#111

I'm sure you get the picture.

list_to_integer("1000", 2)
list_to_integer("1001", 2)
list_to_integer("1010", 2)
list_to_integer("1011", 2)

I'm sure you get that picture too.

In your example
<<1:1/bitstring, ...
I see two integers but I do not see a bit string.
<<1:1, 1:1, 0:1, 0:1>>
<<1:1, 1:1, 0:1, 1:1>>
<<1:1, 1:1, 1:1, 0:1>>
<<1:1, 1:1, 1:1, 1:1>>

but that cannot be what you want because you asked
about making binary numbers, and the binaries you get
are not numbers.

On Fri, 10 Dec 2021 at 05:05, Java House <java4dev@REDACTED> wrote:

> Hello
>
> I am trying to build a binary number but I cannot find the correct way:
> 13> <<1:1/bitstring,
> 0:1/bitstring,0:1/bitstring,0:1/bitstring,0:1/bitstring,0:1/bitstring,0:1/bitstring,0:1/bitstring>>.
> ** exception error: bad argument
>      in function  eval_bits:eval_exp_field1/6 (eval_bits.erl, line 123)
>      in call from eval_bits:create_binary/2 (eval_bits.erl, line 81)
>      in call from eval_bits:expr_grp/4 (eval_bits.erl, line 72)
>
> How do we build a binary number e.g.
> 10000000 or 10101010 or even a binary number that is not just 8 bit but
> 12, 14 or 17 bit long
>
> Kind Regards
> Nikolas
>
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