Split flat array into grouped subarrays containing values from consecutive key in the input array

I have an array from array_diff function and it looks like below:

Array
(
    [0] => world
    [1] => is
    [2] => a
    [3] => wonderfull
    [5] => in
    [6] => our
)

As you can see, we have a gap between the keys #3 and #5 (i.e. there is no key #4). How can I split that array into 2 parts, or maybe more if there are more gaps? The expected output would be:

Array
    (
        [0] => Array
        (
           [0] => world
           [1] => is
           [2] => a
           [3] => wonderfull
        )
        [1] => Array 
        (
           [0] => in
           [1] => our
        ) 
    )

Answer

You can use old_key,new_key concept to check that there difference is 1 or not? if not then create new index inside you result array otherwise add the values on same index:-

<?php

$arr = Array(0 => 'world',1 => 'is',2 => 'a',3 => 'wonderfull',5 => 'in',6 => 'our');

$new_array = [];
$old_key = -1;
$i = 0;
foreach($arr as $key=>$val){
    if(($key-$old_key) ==1){
        $new_array[$i][] = $val;
        $old_key = $key;
    }
    if(($key-$old_key) >1){
         $i++;
         $new_array[$i][] = $val;
         $old_key = $key;
    }
}
print_r($new_array);

https://3v4l.org/Yl9rp