$a = array('apple' => 1, 'ibm' => 2, 'sun' => 3);
$flipped = array_flip($a);
print_r($flipped);
/*
Array (
	[1] => apple
	[2] => ibm
	[3] => sun
)
*/

hash = { "apple" => 1, "ibm" => 2, "sun" => 3 };
flipped = hash.invert;
p flipped;
# => {1 => "apple", 2 => "ibm", 3 => "sun"}

$array = array('go' => 'green', 'stop' => 'red');
var_dump( array_keys($array) );
/*
Array (
	[0] => go
	[1] => stop
)
*/

array = { :go => 'green', :stop => 'red' };
puts array.keys;
# => [:go, :stop]

$users = array('john', 'jane', 'tim', 'alex');
$lucky_winner = array_rand($users);
echo $lucky_winner;
// alex

users = [ 'john', 'jane', 'tim', 'alex' ];
lucky_winner = users[rand(users.length)];
puts lucky_winner;
# => alex

$a = array('php', 'ruby', 'java');
$results = array_reverse($a);
print_r($results);
/*
Array (
	[0] => 'java'
	[1] => 'ruby'
	[2] => 'php'
)
*/

a = [ "php", "ruby", "java" ];
p a.reverse;
# => ["java", "ruby", "php"]

$a = array('a', 'b','a', 'c', 'c');
$results = array_count_values($a);
print_r($results);
/*
Array (
	[a] => 2
	[b] => 1
	[c] => 2
)
*/

a = [ "a", "b", "a", "c", "c" ];
result = list.inject({}) do |hash, key|
  hash.include?(key) ? hash[key] += 1 : hash[key] = 1;
  hash
end
 
p result;
# => ["a" => 2, "b" => 1, "c" => 2]

$langs = array('php', 'ruby', 'java', 'perl', 'csharp');
$my_size = 2;
var_dump( array_chunk($langs, $my_size) );
 
/*
Array (
    [0] => Array
        (
            [0] => php
            [1] => ruby
        )
 
    [1] => Array
        (
            [0] => java
            [1] => perl
        )
 
    [2] => Array
        (
            [0] => csharp
        )
 
) )
*/

def array_chunk(full_array, size)
        number_of_chunks = (full_array.length/size.to_f).ceil;
        chunks = (1..number_of_chunks).collect { [] }
            while full_array.any?
              chunks.each do |a_chunk|
                a_chunk << full_array.shift if full_array.any?
              end
            end
        chunks
end
 
langs = ["php", "ruby", "java", "perl", "csharp"]
my_size = 2
p array_chunk(langs, my_size)
 
# => [["php", "perl"], ["ruby", "csharp"], ["java"]]

$my_array = array('a', 'b', 'c', 'd');
$my_element = array_shift($my_array);
print_r($my_element);
/*
Array (
	[0] => a
)
*/

my_array = [ "a", "b", "c", "d" ];
puts my_array.shift;
# => ["a"]

$elements = array('php', 'ruby', 'perl', 'php');
array_unique($elements);
print_r($elements);
/*
Array (
	[0] => php
	[1] => ruby
	[2] => perl
)
*/

elements = [ "php", "ruby", "perl", "php" ];
puts elements.uniq;
# => ["php", "ruby", "perl"]

$cue = array('http', 'https', 'ftp');
array_unshift($cue, 'ssh');
print_r($cue);
/*
Array (
	[0] => ssh
	[1] => http
	[2] => https
	[3] => ftp
)
*/

cue = [ "http", "https", "ftp" ];
cue.unshift('ssh');
puts cue;
# => [ "ssh", "http", "https", "ftp"]

$langs = array('php', 'ruby', 'perl');
list($lang1, $lang2, $lang3) = $langs;
echo $lang1;	// php
echo $lang2;	// ruby
echo $lang3;	// perl

langs = [ "php", "ruby", "perl" ];
lang1, lang2, lang3 = langs;
puts lang1;	# php
puts lang2;	# ruby
puts lang3;	# perl