How do I create a hash of hashes in Perl?

Question

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} = \         


        

Answer 1

Hashes of hashes are tricky to get right the first time. In this case

$a{1} = { %b };
...
$a{2} = { %b };

will get you where you want to go.

See perldoc perllol for the gory details about two-dimensional data structures in Perl.