shell scripts, spaces, and backslashes

[Bruno Haible via Gnulib discussion list]

I wrote:
> Stackoverflow [1] says that word-expansion must be
> avoided, because it does not support the spaces in arguments

These two examples show how non-intuitive shell scripts behave,
regarding spaces and backslashes in arguments:

$ printf '%s\n' a\\bc\ d\\ef
a\bc d\ef

$ var='a\\bc\ d\\ef'
$ printf '%s\n' $var
a\\bc\
d\\ef

Good luck understanding this!