Merge all sub arrays into one [duplicate]

Question

I'm looking to find a way to merge all child arrays into one large array.

array ( [0] = [0] = '0ARRAY', [1] = '1ARRAY' [1] = [0] = '2ARRAY', [1] = '3ARRAY' )

into

array ( [0] = '0ARRAY', [1] = '1ARRAY', [2] = '2ARRAY', [3] = '3ARRAY' )

Without using array_merge($array[0],$array[1]) because I don't know how many arrays there actually are. So I wouldn't be able to specify them.

Thanks

Rangad · Accepted Answer · 2014-12-04 21:14:05Z

If I understood your question:

php 5.6+

$array = array( array('first', 'second'), array('next', 'more') ); $newArray = array_merge(...$array);

Outputs:

array(4) { [0]=> string(5) "first" [1]=> string(6) "second" [2]=> string(4) "next" [3]=> string(4) "more" }

php < 5.6

$newArray = call_user_func_array('array_merge', $array);

If anyone intrested where ... "splat" operator is documented: regarding general issue - "Argument Unpacking" wiki.php.net/rfc/argument_unpacking , official mention is also here: php.net/manual/en/migration56.new-features.php
With fix for empty $array: $newArray = array_merge(...$array ?: [[]]);

Mark Baker · Accepted Answer · 2014-12-04 21:13:02Z

38

If it's only two levels of array, you can use

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

which should work as long as $array isn't completely empty

answered Dec 4, 2014 at 21:13

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3 Comments

Best solution if found too : $array is then used as a list or arguments to the array_merge() function

With fix for empty $array: $result = call_user_func_array('array_merge', $array ?: [[]]);

php8 Fatal error: Uncaught ArgumentCountError: array_merge() does not accept unknown named parameters

RNK · Accepted Answer · 2014-12-04 21:12:27Z

$new_array = array(); foreach($main_array as $ma){ if(!empty($ma)){ foreach($ma as $a){ array_push($new_array, $a); } } }

You can try it by placing these values:

$main_array[0][0] = '1'; $main_array[0][1] = '2'; $main_array[1][0] = '3'; $main_array[1][1] = '4';

OUTPUT:

Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 )