How to show parent and child items form array in php - php

Question

I am new at php. Maybe a simple question.. I want to make parent->child view. I have an array like this:
With key id and key parent.
How to draw in cycle correct structure? Maybe at first I need to create function for creating the tree ?
-Apple
-Services
Duster
array(3) {
[0]=>
array(6) {
["id"]=>
string(3) "127"
["title"]=>
string(5) "Apple"
["deleted"]=>
string(1) "0"
["parent"]=>
NULL
["usp_id"]=>
string(3) "445"
["user_id"]=>
NULL
}
[1]=>
array(6) {
["id"]=>
string(3) "159"
["title"]=>
string(14) "Renault Duster"
["deleted"]=>
string(1) "0"
["parent"]=>
NULL
["usp_id"]=>
string(3) "495"
["user_id"]=>
NULL
}
[2]=>
array(6) {
["id"]=>
string(1) "7"
["title"]=>
string(8) "Services"
["deleted"]=>
string(1) "0"
["parent"]=>
string(3) "127"
["usp_id"]=>
string(2) "79"
["user_id"]=>
string(3) "275"
}
}

Answer 1

Cycle through the source array $arr to detect records that have a parent (not null). When a child record is found, push it into the parent.
foreach ($arr as $key0 => $record) {
if (null !== $record['parent']) {
foreach ($arr as $key1 => $parent) {
if ($parent['id'] === $record['parent']) {
$arr[$key1]['children'][] = $record; // push child into parent
unset($arr[$key0]); // delete child
}
}
}
}
demo

Answer 2

A simple and common idea is to prepare your data for easy printing. In your case, you need to group your data so that each item includes parent and children data.
Create a temporary array ($temp). Each item would be something like this:
['id' =>, 'name' => '', children => ['name' => '']]
And iterate through your original array ($curr) two times.
First pass:
parent is not null:
$temp[$curr['parent']]['children'][] = ['name' => $curr['name']]
parent is null:
$temp[$curr['id']] = ['name' => $curr['name'], 'children' => []]
In the second pass simply print it since you already have everything grouped.