bottles.php

#!/usr/bin/php
<?php
    function bottle (&$i) {
        $bottle;
        
        switch ($i) {
            case ($i == 1):
                $bottle = 'bottle';
                break;
            default:
                $bottle = 'bottles';
        }
        
        return $bottle;
    }
    
    $i = 99;
    while ($i > 0) {
        echo "$i " . bottle($i) . " of beer on the wall, $i " . bottle($i) . " of beer\n";
        $i--;
        echo "take one down, pass it around, $i " . bottle($i) . " of beer on the wall\n";    
    }
?>

bottles.pl

#!/usr/bin/perl

use strict;
use warnings;
use feature ':5.10';

my $i = 99;
while ($i > 0) {
    say "$i " . bottles($i) . " of beer on the wall, $i " . bottles($i) . " of beer.";
    $i--;
    say "take one down, pass it around, $i " . bottles($i) . " of beer on the wall.";
}

sub bottles {
    my $i = shift;
    my $bottle;
    
    given ( $i ) {
        when    ($i == 1) {$bottle = 'bottle';}
        default           {$bottle = 'bottles';}
    }

    return $bottle;
}

bottles.py

#!/usr/bin/python

def bottle(n):      # Return bottle or bottles, appropriately
    """Return bottle or bottles, appropriately"""
    bot = ''

    if n == 1:
        bot = 'bottle'
    else:
        bot = 'bottles'

    return bot

i = 99
while i > 0:
    print i, bottle(i), "of beer on the wall.", i, bottle(i), "of beer."
    i = i - 1
    print "take one down, pass it around,", i, bottle(i), "of beer on the wall"

bottles.rb

#!/usr/bin/env ruby

def bottle(i)
  bot = String.new
  
  case i
  when 1
    bot = 'bottle'
  else
    bot = 'bottles'
  end

  bot
end

i = 99
while (i > 0)
  puts "#{i.to_s} #{bottle(i)} of beer on the wall, #{i.to_s} #{bottle(i)} of beer."
  i = i - 1
  puts "Take one down, pass it around, #{i.to_s} #{bottle(i)} of beer on the wall."
end