1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

perl -wE'for (1..20) { $hash{$_}++; say scalar %hash; }'
1/8
2/8
3/8
3/8
4/8
5/8
6/8
7/16
8/16
9/16
10/16
10/16
10/16
11/16
11/16
14/32
14/32
15/32
15/32
15/32

Quote

If you evaluate a hash in scalar context, it returns false if the hash is empty. If there are any
key/value pairs, it returns true; more precisely, the value returned is a string consisting of the
number of used buckets and the number of allocated buckets, separated by a slash.

Always code as if the guy who ends up maintaining your code will be a violent psychopath who knows where you live. -- Damian Conway in "Perl Best Practices"
lesen: Wie frage ich & perlintro brian's Leitfaden für jedes Perl-Problem