Sorting Multidimensional array several levels - php

Question

I am currently trying to sort a multidimensional array by its totalPoints. Each array lineupSet has an n amount of items. I am trying to get the lineupSet with the the highest total totalPoints. How could I achieve most efficiently? the below is sudocode and therefore not working. Unsure how to approach this.
Code
public function getHighestTotalPoints($testArray)
{
if (isset($testArray) && !empty($testArray)) {
uasort($testArray, function ($a, $b) {
return $a['lineupSet']['formula']['totalPoints'] <=> $b['lineupSet']['formula']['totalPoints'] ;
});
return array_reverse($testArray);
}
return null;
}
$testArray = [[
"lineupSet" => [
[[
"formula" => [
"totalPoints" => 214.61,
],
"name" => "test1",
], [
"formula" => [
"totalPoints" => 201.17,
],
"name" => "test2",
]], [
"formula" => [
"totalPoints" => 5.01,
],
"name" => "test3",
]],
], [
"lineupSet" => [
[[
"formula" => [
"totalPoints" => 220.66,
],
"name" => "test1",
], [
"formula" => [
"totalPoints" => 214.76,
],
"name" => "test2",
]],
],
], [
"lineupSet" => [
[[
"formula" => [
"totalPoints" => 205.71,
],
"name" => "test1",
], [
"formula" => [
"totalPoints" => 204.43,
],
"name" => "test2",
]],
],
], [
"lineupSet" => [
[[
"formula" => [
"totalPoints" => 205.48,
],
"name" => "test1",
], [
"formula" => [
"totalPoints" => 203.51,
],
"name" => "test2",
]],
],
]];
Desired result:
[0] => Array
(
[lineupSet] => Array
(
[0] => Array
(
[0] => Array
(
[formula] => Array
(
[totalPoints] => 220.66
)
[name] => test1
)
[1] => Array
(
[formula] => Array
(
[totalPoints] => 214.76
)
[name] => test2
)
)
)
)

Answer 1

You can use usort to sort the array according to a custom function. This function determines the totalPoints for a given lineupSet:
function sum_points($v) {
$totalPoints = 0;
foreach ($v['lineupSet'] as $lset) {
if (isset($lset['formula'])) {
$totalPoints += $lset['formula']['totalPoints'];
}
else {
foreach ($lset as $l) {
$totalPoints += $l['formula']['totalPoints'];
}
}
}
return $totalPoints;
}
To sort descending (so the maximum total points is in the first entry of the array), we then use a sort function which returns a positive number when the second value's totalPoints are bigger than the first, a negative number when it's smaller and 0 when they are the same:
function sort_points($a, $b) {
return sum_points($b) - sum_points($a);
}
Finally we call usort with this function and output the first element of the array:
usort($testArray, 'sort_points');
print_r($testArray[0]);
Output:
Array (
[lineupSet] => Array
(
[0] => Array
(
[0] => Array
(
[formula] => Array
(
[totalPoints] => 220.66
)
[name] => test1
)
[1] => Array
(
[formula] => Array
(
[totalPoints] => 214.76
)
[name] => test2
)
)
)
)
Demo on 3v4l.org