[erlang-questions] Binaries and "strings"

Robert Virding <>
Fri Feb 26 23:42:49 CET 2010

On 26 February 2010 23:33, Steve Davis <> wrote:
> Found this binary behavior interesting:
> 1> <<"one", "two">>.
> <<"onetwo">>

This creates a binary containing the characters (bytes) of the two string.

> 2> <<"one" "two">>.
> <<"onetwo">>

Here the two string are concatenated to one already in the parser, so
you are actually writing <<"abcdef">>. This is feature is useful as it
allows you to split a long string into many sub strings without extra
computational cost.

You can also write "abc" ++ "def" in code and the compiler will
optimise away the ++. It can always do this if the first argument to
++ is a list literal.


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