use Devel::Size qw(size); use Devel::Peek; sub info { print Dump($_[0]); print "size = ",size($_[0])," ($_[1])\n\n"; } $num = 123; # or int("123") info($num, "integer"); $num .= ""; info($num, "integer stringified"); $str = "123"; info($str, "string"); $str += 0; info($str, "string numified"); $str += 45678900; info($str, "... with bigger integer"); $str .= ""; info($str, "... re-stringified");