Split an array into a MD array every nth line - php

Question

bit of a question here. Ive got an array that contains data which has been parsed from a website using all our favourite php functions such as array_map.
The array is current 3 sub arrays deep.
Here is the code I am using:
for ($tcid = 1; $tcid <= count($categories); $tcid++) {
$catHeader[$tcid] = $categories[$tcid][0];
$event[$i]['tickets'] = $categories;
unset($categories[$tcid][0]);
$categories[$tcid] = array_map('trim', $categories[$tcid]);
$categories[$tcid] = array_values($categories[$tcid]);
$ab = 0;
for ($b = 0; $b <= count($categories[$tcid]); $b++) {
if ($categories[$tcid][$b] == "" || !$categories[$tcid][$b] || $categories[$tcid][$b] == null) {
unset($categories[$tcid][$b]);
}
}
}
and the array looks something like....
[1] => Array (
[data] => Array ( ...
)
[tickets] => Array (
[1] => Array (
[0] => xxx
[1] => etc
[3] => etc2
)
[2] => (
[0] => Std1
[1] => 10 / 10
[2] => £20.00
[3] => £200.00
[4] => Std2
[5] => 100 / 100
[6] => £13.00
[7] => £1,300.00
[8] => Std3
[9] => 10 / 320
[10] => £15.00
[11] => £150.00
)
)
)
My question to you today, is how on earth do I split the array every 4 \n's or array keys as they're known and explode each 4 into a further sub array?
So that Std1, Std2, Std3 will be their own sub array with its associated data of the 2nd key of tickets, but also doing this for every sub array of tickets that has more than 1 set of data (a set of data being 4 array keys).
I've tried all sorts but can't get it to work.
See below of how I want it to look.
[1] => Array (
[data] => Array ( ...
)
[tickets] => Array (
[1] => Array (
[0] => xxx
[1] => etc
[3] => etc2
)
[2] => (
[0] => Array (
[0] => Std1
[1] => 10 / 10
[2] => £20.00
[3] => £200.00
)
[1] => Array (
[0] => Std2
[1] => 100 / 100
[2] => £13.00
[3] => £1,300.00
)
[2] => Array (
[0] => Std3
[1] => 10 / 320
[2] => £15.00
[3] => £150.00
)
)
)
)
Thanks

Answer 1

As noted in the comments, you'd be best off handling your array by-reference to modify it's original contents somewhere within your loops
Provided the array groupings you want to chunk are in groups of 4, you could array_chunk() it:
$array['tickets'][2] = array_chunk($array['tickets'][2], 4);