Based on my current understanding of hashes in Perl, I would expect this code to print "hello world." It instead prints nothing.
%a=();
%b=();
$b{str} = "hello";
$a{1}=%b;
$b=();
$b{str} = "world";
$a{2}=%b;
print "$a{1}{str} $a{2}{str}";
I assume that a hash is just like an array, so why can't I make a hash contain another?
You should always use "use strict;" in your program.
Use references and anonymous hashes.
use strict;use warnings;
my %a;
my %b;
$b{str} = "hello";
$a{1}={%b};
%b=();
$b{str} = "world";
$a{2}={%b};
print "$a{1}{str} $a{2}{str}";
{%b}
creates reference to copy of hash %b
. You need copy here because you empty it later.