=head1 NAME
-perlfaq4 - Data Manipulation ($Revision: 1.8 $, $Date: 2001/11/09 08:06:04 $)
+perlfaq4 - Data Manipulation ($Revision: 1.9 $, $Date: 2001/12/07 21:17:58 $)
=head1 DESCRIPTION
=head2 How can I know how many entries are in a hash?
If you mean how many keys, then all you have to do is
-take the scalar sense of the keys() function:
+use the keys() function in a scalar context:
- $num_keys = scalar keys %hash;
+ $num_keys = keys %hash;
-The keys() function also resets the iterator, which in void context is
-faster for tied hashes than would be iterating through the whole
-hash, one key-value pair at a time.
+The keys() function also resets the iterator, which means that you may
+see strange results if you use this between uses of other hash operators
+such as each().
=head2 How do I sort a hash (optionally by value instead of key)?
=head1 NAME
-perlfaq6 - Regexes ($Revision: 1.4 $, $Date: 2001/11/09 08:06:04 $)
+perlfaq6 - Regexes ($Revision: 1.5 $, $Date: 2001/12/02 01:55:12 $)
=head1 DESCRIPTION