Use foreach() Loops

• foreach implicitly aliases and localizes:

      foreach $e (@a, @b) { $e *= 3.14159 }
      for (@lines) {
          chomp;
          s/fred/barney/g;
          tr[a-z][A-Z];
      }
  

• Remember you can copy and modify all at once:

      foreach $n (@square = @single) { $n **= 2 }