perl-data-structures

I know about the hash use of the => operator, like this $ cat array.pl %ages = ('Martin' => 28, 'Sharon' => 35, 'Rikke' => 29,); print "Rikke is $ages{Rikke} years old\n"; $ perl array.pl Rikke is 29 years old $ and I thought it was just syntax to initialize hashes, but in answers to How can I qualify a variable as const/final in Perl? , => has been used like this use Readonly; Readonly my $infilename => "input_56_12.txt"; What exactly does => mean? Are there more ways in which => can be used? The => operator in perl is basically the same as comma. The only difference is that if there's an

I have two data structures in Perl: An array: my @array2 = ( "1", "2", "3"); for $elem (@array2) { print $elem."\n"; } Giving me the following output: 1 2 3 And a list: my @array = [ "1", "2", "3"]; for $elem (@array) { print $elem."\n"; } Giving the following output: ARRAY(0x9c90818) Obviously, I'd like to iterate over the elements in both cases, but why does the second solution give me only the reference to this array? Lists in Perl are not data structures, they are positions in the source code, determined by the context around them. Lists are basically the transient structures that Perl