クロージャ/ラムダを Ruby,PHP5.2,PHP5.3 で使用した場合と使用しない場合の単純な比較

closure.php

#!/usr/bin/env php
<?php

# for PHP 5.3 use "Closure"
$strtoupper = function($s) { return strtoupper($s); };

$fruits = array('apple', 'orange', 'cherry');
$stars  = array('sun', 'moon', 'earch');

echo implode('-', array_map($strtoupper, $fruits)) . "\r\n";  // APPLE-ORANGE-CHERRY
echo implode('-', array_map($strtoupper, $stars)) . "\r\n";  // SUN-MOON-EARCH

create_function.php

#!/usr/bin/env php
<?php

# for PHP 5.2 use "create_funciton"
$strtoupper = create_function('$s', 'return strtoupper($s);');

$fruits = array('apple', 'orange', 'cherry');
$stars  = array('sun', 'moon', 'earch');

echo implode('-', array_map('strtoupper', $fruits)) . "\r\n"; // APPLE-ORANGE-CHERRY
echo implode('-', array_map('strtoupper', $stars)) . "\r\n"; // SUN-MOON-EARCH

lambda.rb

#!/usr/bin/env ruby

upcase = lambda { |s| s.upcase! }

fruits = ['apple', 'orange', 'cherry']
stars  = ['sun', 'moon', 'earth']

p fruits.each(&upcase).join('-') # "APPLE-ORANGE-CHERRY"
p stars.each(&upcase).join('-') # "SUN-MOON-EARTH"

normal_function.php

#!/usr/bin/env php 
<?php

function strtouppers($array)
{
    foreach($array as &$string) {
        $string = strtoupper($string);
    }

    return $array;
}

$fruits = array('apple', 'orange', 'cherry');
$stars  = array('sun', 'moon', 'earch');

echo implode('-', strtouppers($fruits)) . "\r\n";  // APPLE-ORANGE-CHERRY
echo implode('-', strtouppers($stars)) . "\r\n"; // SUN-MOON-EARCH

not_lambda.rb

#!/usr/bin/env ruby

def upcases(array)
  array.each { |s| s.upcase! }
end

fruits = ['apple', 'orange', 'cherry']
stars = ['sun', 'moon', 'earth']
 
p upcases(fruits).join('-') # "APPLE-ORANGE-CHERRY"
p upcases(stars).join('-') # "SUN-MOON-EARTH"

# or 

p fruits.each { |s| s.upcase } .join('-') # "APPLE-ORANGE-CHERRY"
p stars.each { |s| s.upcase } .join('-') # "SUN-MOON-EARTH"