Question

perldoc says “a list assignment in scalar context returns the number of elements on the right-hand side of the list assignment” but when I try this code:

perl -e '$_="aaaaa";print $v=(()=split //)'

The output is 1 which makes me confused. (The answer I expect is 5.)

Can anybody explain this?

Answer 1

According to split documentation:

When assigning to a list, if LIMIT is omitted, or zero, Perl supplies
a LIMIT one larger than the number of variables in the list <…>

Since you specify empty list, split only returns 1 result and this number of results is exactly what ends in your variable.