in reply to
Re^4: Occurence List
in thread Occurence List
when you write
$ perl -le " use warnings; use strict; my $foo; $foo++; print $foo "
you declare $foo by saying my $foo; and then do something with it($foo++). Of course $foo++ would then not cause autovivication, because $foo already exists.
The thing with array indexes and hash keys, is that we do not have to declare them before we can use them. There is no need to say my $bar;, or even my $bar++; before you can assign anything to it.