sort multilevel array php - php

Question

I have the following array:
array(
array(
id: 4,
name: car,
pid: 0
),
array(
id: 5,
name: lights,
pid: 4
),
array(
id: 6,
name: fog,
pid: 5
)
),
array(
array(
id: 1,
name: bike,
pid: 0
),
array(
id: 2,
name: wheel,
pid: 1
),
array(
id: 3,
name: tire,
pid: 2
)
),
array(
id: 7,
name: car,
pid: 0
),
array(
id: 8,
name: lights,
pid: 7
),
array(
id: 9,
name: brake,
pid: 8
)
),
array(
id: 10,
name: car,
pid: 0
),
array(
id: 11,
name: engine,
pid: 10
)
),
)
These multidimesnional array represent the specifications of a car. In a table, it looks like:
| car -> lights -> fog |
| bike -> wheel -> tire |
| car -> lights -> brake |
| car -> engine |
And now I would like to sort the array, for each level on name. So first, sort on the first column, than sort on the second column etc...
Our sorted array should look like:
| bike -> wheel -> tire |
| car -> engine |
| car -> lights -> brake |
| car -> lights -> fog |
Using usort I can sort on the first column:
usort($characteristics, function($a, $b){
return $a[0]['name'] > $b[0]['name'];
});
But offcourse this only affects the first column and in this case, the array looks like:
| bike -> wheel -> tire |
| car -> lights -> fog |
| car -> lights -> brake |
| car -> engine |
It is also possible to have different lengths (like the engine, that has 2 values, and the bike, which has 3). Normally the length varies between 1 and 5.
I rather wouldn't use too much for/foreach loops, because that would slow my program too much. Also sorry for the long question, but I couldn't find a shorter way to explain my problem.
I hope someone can give me e simple clean solution.

Answer 1

I believe this is what you are looking for:
$arr =
array(
array(
array(
"id" => 4,
"name" => "car",
"pid" => 0
),
array(
"id" => 5,
"name" => "lights",
"pid" => 4
),
array(
"id" => 6,
"name" => "fog",
"pid" => 5
)
),
array(
array(
"id" => 1,
"name" => "bike",
"pid" => 0
),
array(
"id" => 2,
"name" => "wheel",
"pid" => 1
),
array(
"id" => 3,
"name" => "tire",
"pid" => 2
)
),
array(
array(
"id" => 7,
"name" => "car",
"pid" => 0
),
array(
"id" => 8,
"name" => "lights",
"pid" => 7
),
array(
"id" => 9,
"name" => "brake",
"pid" => 8
)
),
array(
array(
"id" => 10,
"name" => "car",
"pid" => 0
),
array(
"id" => 11,
"name" => "engine",
"pid" => 10
)
)
);
for ($i = 0; $i < count($arr); $i++) {
foreach ($arr[$i] as $a) {
foreach($a as $key => $value) {
if ($key == 'name') {
$newArr[$i][] = $value;
}
}
}
}
usort($newArr, function($a, $b) {
return $a[0] > $b[0];
});
echo "<pre>", print_r($newArr), "</pre>";