Returning multiple values from a function (Perl, PHP, Python)

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Returning multiple values from a function (Perl, PHP, Python)

Archive - Originally posted on "The Horse's Mouth" - 2007-05-24 18:39:40 - Graham Ellis
Function in PHP and Python and subs in Perl can only return one "thing" - one item, one object. But all three languages allow that returned item to be a collection - in other words, a composite. And all three languages provide a very easy way of breaking the returned structure down into a series of individual variables.

Python Example returning a tuple

# Returning a tuple from a function

def doingit(v):

  a = v+10

  b= v*20

  c = 56/v

  return c,a,b;   # returns a tuple

# function call will return a tuple (into z)

z = doingit(7)

# This syntax splits the tuple out into a

# series of individual variables (w, l and k)

w,l,k = doingit(7)

# Show that it has worked as expected

print w, l, k

print z

PHP Example returning into the list function

<?php

function maykit() {

  $rv = array("4","15");

  array_push($rv,"William");

  return $rv;

  }

list($fno,$sno,$name) = maykit();

print "We have $fno and $sno for $name\n";

?>

Perl Example Saving the returned values to a list

sub sistance {

  my @n;

  $n[0] = 4;

  $n[1] = 17;

  $n[2] = 23;

  return @n;

  }

($first,$second,$third) = sistance();

print "We have $first and $second and $third\n";

In each case, the techniques shown above should be used when you want to return multiple values in strong preference to global variables - your code will be much more modular and easy to maintain if you follow the approach shown.