Tricks of the Wizards

Magical Exporter Variable

Magic hash is not limited to evaluation:

     package Format_Money;

     sub FETCH {
       my ($dummy, $amount) = @_;
       my ($dollars, $cents) = split /\./, sprintf("%.2f", $amount);
       1 while $dollars =~ s/^([-+]?\d+)(\d{3})/$1,$2/;     # FAQ
       "\$$dollars.$cents";
     }

Now:

     use Format_Money;

     $salary = 43_000;
     print "After your raise, you will make $Money{$salary*1.06}.\n";

        After your raise, you will make $45,580.00

Also use for automatic URL character escaping (for example)
Also see Interpolation module