PHP - How to merge arrays inside array

Question 1

How to merge n number of array in php. I mean how can I do the job like :
array_merge(from : $result[0], to : $result[count($result)-1])
OR
array_merge_recursive(from: $result[0], to : $result[count($result) -1])

Where $result is an array with multiple arrays inside it like this :

$result = Array(
0 => array(),//associative array
1 => array(),//associative array
2 => array(),//associative array
3 => array()//associative array
)

My Result is :

$result = Array(
    0 => Array(
        "name" => "Name",
        "events" => 1,
        "types" => 2
    ),
    1 => Array(
        "name" => "Name",
        "events" => 1,
        "types" => 3
    ),
    2 => Array(
        "name" => "Name",
        "events" => 1,
        "types" => 4
    ),
    3 => Array(
        "name" => "Name",
        "events" => 2,
        "types" => 2
    ),
    4 => Array(
        "name" => "Name",
        "events" => 3,
        "types" => 2
    )
)

And what I need is

$result = Array(
"name" => "name",
"events" => array(1,2,3),
"types" => array(2,3,4)
)

Question 2

array_merge can take variable number of arguments, so with a little call_user_func_array trickery you can pass your $result array to it:

$merged = call_user_func_array('array_merge', $result);

This basically run like if you would have typed:

$merged = array_merge($result[0], $result[1], .... $result[n]);

Update:

Now with 5.6, we have the ... operator to unpack arrays to arguments, so you can:

$merged = array_merge(...$result);

And have the same results. *

* The same results as long you have integer keys in the unpacked array, otherwise you'll get an E_RECOVERABLE_ERROR : type 4096 -- Cannot unpack array with string keys error.

Question 3

$output = array();

$arrayAB = array_merge($arrayA, $arrayB);
foreach ( $arrayAB as $value ) {
  $id = $value['id'];
  if ( !isset($output[$id]) ) {
    $output[$id] = array();
  }
  $output[$id] = array_merge($output[$id], $value);
}

var_dump($output);

Optionally if you want to reset output's keys, just do:

$output = array_values($output);

Question 4

By assigning temporary keys, you can determine whether you are dealing with the first occurrence or not and then use the appropriate technique to either store the whole subarray or merely add value to the price element of the subarray.

Code: (Demo)

$to_account = [
  [ 'account' => 251234567890, 'price' => 83 ],
  [ 'account' => 251234567890, 'price' => 27 ],
  [ 'account' => 251234564526, 'price' => 180 ],
  [ 'account' => 251234567890, 'price' => 40 ]
];

foreach ($to_account as $row) {
    if (!isset($result[$row['account']])) {
        $result[$row['account']] = $row;
    } else {
        $result[$row['account']]['price'] += $row['price'];
        // imitate the above line if there was another column to sum
    }
}
var_export($result);

Output:

array (
  251234567890 => 
  array (
    'account' => 251234567890,
    'price' => 150,
  ),
  251234564526 => 
  array (
    'account' => 251234564526,
    'price' => 180,
  ),
)

This method does not bother to overwrite redundant account element values. To reindex the output array, merely call array_values() on it.

Question 5

This should do it, if I'm understanding your logic correctly:

array_intersect_key($changed, $filtered) + $filtered

Implementation:

$filtered = array(1 => 'a', 3 => 'c');
$changed = array(2 => 'b*', 3 => 'c*');
$expected = array(1 => 'a', 3 => 'c*');    
$actual = array_key_merge_deceze($filtered, $changed);

var_dump($expected, $actual);

function array_key_merge_deceze($filtered, $changed) {
    $merged = array_intersect_key($changed, $filtered) + $filtered;
    ksort($merged);
    return $merged;
}

Output:

Expected:
array(2) {
  [1]=>
  string(1) "a"
  [3]=>
  string(2) "c*"
}

Actual:
array(2) {
  [1]=>
  string(1) "a"
  [3]=>
  string(2) "c*"
}

Question 6

If both arrays are in the same order, the code is pretty straightforward:

$a = array(
    array('5/2/2013', '9:31:00 AM', '0.395', '0.395', '302.855', '0.563'),
    array('5/2/2013', '9:33:00 AM', '0.383', '0.383', '303.431', '0.563'),
);

$b = array(
    array('5/2/2013', '9:31:00 AM', '-1.000', '-1.000', '-1.000', '-1.670', '-1.000', '-11.000'),
    array('5/2/2013', '9:33:00 AM', '-1.000', '-1.000', '-1.000', '-1.670', '-1.000', '-11.000'),
);


$i = new MultipleIterator(MultipleIterator::MIT_NEED_ALL | MultipleIterator::MIT_KEYS_ASSOC);
$i->attachIterator(new ArrayIterator($a), 'a');
$i->attachIterator(new ArrayIterator($b), 'b');

$result = [];
foreach ($i as $v) {
    $result[] = array_merge($v['a'], array_slice($v['b'], 2));
}
print_r($result);

You basically iterate over both arrays at the same time and for each element construct the final array by merging the first with the second (skipping the common part).

Result:

Array
(
    [0] => Array
        (
            [0] => 5/2/2013
            [1] => 9:31:00 AM
            [2] => 0.395
            [3] => 0.395
            [4] => 302.855
            [5] => 0.563
            [6] => -1.000
            [7] => -1.000
            [8] => -1.000
            [9] => -1.670
            [10] => -1.000
            [11] => -11.000
        )

    [1] => Array
        (
            [0] => 5/2/2013
            [1] => 9:33:00 AM
            [2] => 0.383
            [3] => 0.383
            [4] => 303.431
            [5] => 0.563
            [6] => -1.000
            [7] => -1.000
            [8] => -1.000
            [9] => -1.670
            [10] => -1.000
            [11] => -11.000
        )
)

PHP - How to merge arrays inside array

Answers

Update:

php,array-merge