Perl Style: Embrace && and || for Control and Values

Jan 1, 1998 by Tom Christiansen

• Perl’s && and || operators short circuit like C’s, but return different values: they return the first thing that resolves them.

• This is most often used with ||:

      ++$count{ $shell || "/bin/sh" };
  
      $a = $b || 'DEFAULT';
  
      $x ||= 'DEFAULT';
  

• Sometimes it can be done with && also, usually providing the false value is “ not 0. (False tests in Perl return ” not 0!).

      $nulled_href = $href . ($add_nulls && "\0");
  

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Copyright © 1998, Tom Christiansen All rights reserved.