PHP - Generate all the possible combinations among a set of nested arrays.

combos.php

/**
 * Generate all the possible combinations among a set of nested arrays.
 *
 * @param array $data  The entrypoint array container.
 * @param array $all   The final container (used internally).
 * @param array $group The sub container (used internally).
 * @param mixed $val   The value to append (used internally).
 * @param int   $i     The key index (used internally).
 */
function generate_combinations(array $data, array &$all = array(), array $group = array(), $value = null, $i = 0)
{
    $keys = array_keys($data);
    if (isset($value) === true) {
        array_push($group, $value);
    }

    if ($i >= count($data)) {
        array_push($all, $group);
    } else {
        $currentKey     = $keys[$i];
        $currentElement = $data[$currentKey];
        foreach ($currentElement as $val) {
            generate_combinations($data, $all, $group, $val, $i + 1);
        }
    }

    return $all;
}

$data = array(
    array('a', 'b'),
    array('e', 'f', 'g'),
    array('w', 'x', 'y', 'z'),
);

$combos = generate_combinations($data);
print_r($combos);

output.txt

Array
(
    [0] => Array
        (
            [0] => a
            [1] => e
            [2] => w
        )
 
    [1] => Array
        (
            [0] => a
            [1] => e
            [2] => x
        )
 
    [2] => Array
        (
            [0] => a
            [1] => e
            [2] => y
        )
 
    [3] => Array
        (
            [0] => a
            [1] => e
            [2] => z
        )
 
    [4] => Array
        (
            [0] => a
            [1] => f
            [2] => w
        )
 
    [5] => Array
        (
            [0] => a
            [1] => f
            [2] => x
        )
 
    [6] => Array
        (
            [0] => a
            [1] => f
            [2] => y
        )
 
    [7] => Array
        (
            [0] => a
            [1] => f
            [2] => z
        )
 
    [8] => Array
        (
            [0] => a
            [1] => g
            [2] => w
        )
 
    [9] => Array
        (
            [0] => a
            [1] => g
            [2] => x
        )
 
    [10] => Array
        (
            [0] => a
            [1] => g
            [2] => y
        )
 
    [11] => Array
        (
            [0] => a
            [1] => g
            [2] => z
        )
 
    [12] => Array
        (
            [0] => b
            [1] => e
            [2] => w
        )
 
    [13] => Array
        (
            [0] => b
            [1] => e
            [2] => x
        )
 
    [14] => Array
        (
            [0] => b
            [1] => e
            [2] => y
        )
 
    [15] => Array
        (
            [0] => b
            [1] => e
            [2] => z
        )
 
    [16] => Array
        (
            [0] => b
            [1] => f
            [2] => w
        )
 
    [17] => Array
        (
            [0] => b
            [1] => f
            [2] => x
        )
 
    [18] => Array
        (
            [0] => b
            [1] => f
            [2] => y
        )
 
    [19] => Array
        (
            [0] => b
            [1] => f
            [2] => z
        )
 
    [20] => Array
        (
            [0] => b
            [1] => g
            [2] => w
        )
 
    [21] => Array
        (
            [0] => b
            [1] => g
            [2] => x
        )
 
    [22] => Array
        (
            [0] => b
            [1] => g
            [2] => y
        )
 
    [23] => Array
        (
            [0] => b
            [1] => g
            [2] => z
        )
)

I've modified function to keep your index key, example :
$options = array(
'a' => array('a1','b1'),
'b' => array('a2','b2')
);

the output will be :
Array
(
[0] => Array
(
[a] => a1
[b] => a2
)

[1] => Array
    (
        [a] => a1
        [b] => b2
    )

[2] => Array
    (
        [a] => b1
        [b] => a2
    )

[3] => Array
    (
        [a] => b1
        [b] => b2
    )

)

/**

• Generate all the possible combinations among a set of nested arrays.
  *
• @param array $data The entrypoint array container.
• @param array $all The final container (used internally).
• @param array $group The sub container (used internally).
• @param mixed $val The value to append (used internally).
• @param int $i The key index (used internally).
  */

function generate_combinations(array $data, array &$all = array(), array $group = array(), $value = null, $i = 0,$key = null)
{
$keys = array_keys($data);
if (isset($value) === true) {
$group[$key] = $value;
}
if ($i >= count($data)) {
array_push($all, $group);
} else {
$currentKey = $keys[$i];
$currentElement = $data[$currentKey];
if(count($data[$currentKey]) <= 0) {
generate_combinations($data, $all, $group, null, $i + 1,$currentKey);
} else {
foreach ($currentElement as $val) {
generate_combinations($data, $all, $group, $val, $i + 1,$currentKey);
}
}
}
return $all;
}

Thanks for saving life. -_-

created an account just to thank you.

you are a lifesaver!

I owe you a beer!

I have problem on processing multiple combination array.

Çok teşekkür ederim harikasın