Perl Subroutine

A Perl Subroutine is a software function within a Perl program.

• Example(s):
  • sub get_one() {return "one"}
  • sub get_two() {return ("one", "two")}
  • sub get_max($,$) {if ($_[0] > $_[1]) {return $_[0]} else {return $_[1]}}
  • sub get_max() {my($max) = shift @_; foreach (@_) {if ($_ > $max_so_far) {$max = $_}} return $max}
  • a Perl GetOptions Subroutine.
  • …
• Counter-Example(s)
  • a Python Function.
  • a Java Method.
• See: Perl Data Structure.

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References

2005

• http://perlmeme.org/faqs/perl_thinking/returning.html

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Examples

Return two or more variables

   my ($one, $two) = get_two();

   sub get_two() {
      return ("val_1", "val_2")
   }

Receive a predetermined and finite number variables

   sub receive_two($$) {
      print "WARNING! &receive_two should receive exactly two arguments!\n" if (@_ != 2) ;
      my ($a,$b) = @_;
   }

Receive an indeterminate number variables

   sub receive_indeterminate_number() {
      foreach (@_) { 
          ...
      }
   }

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