如何根据多个条件对数组进行排序？

Question

I'm trying to sort an array prioritizing the closest macros value to the optimal values, ie the element best matching the criteria is id of 200 (but is sorted), looks like all the "points" goes to the prev element instead.

function sorter(array $array, $optimal, $minMax){
    usort($array, function($prev, $curr) use($optimal, $minMax){
    
    $points = ['prev' => 0, 'curr' => 0];

    foreach($curr['macros'] as $macro => $value){                       
        if($value > $minMax[$macro]["minimum"] && $value <= $optimal[$macro]){
            if($macro === "protein"){
                $points['curr'] += 2;
            }
            
            if($macro === "carb" && $value < $prev["macros"][$macro]){
                $points['curr'] += 1;
            }
            
            ++$points['curr'];  
        } else {
            ++$points['prev'];
        }
    }
    
    if($points['prev'] === $points['curr']) return 0;

    return $points['prev'] < $points['curr'] ? -1 : 1;
});

return $array;
}

The protein has a higher priority, with carbs coming second.

http://sandbox.onlinephpfunctions.com/code/77fc35f2fb0b60de9271f7e934a5a8a4aa3b25a3

Answer 1

From your description, it sounds like you want to sort by the closeness of the protein value to optimal, breaking ties by using the lowest carb value. This can be done by taking the abs of the difference between actual and optimal protein values, and if equal, comparing the carb values to find the least:

function sorter(array $array, $optimal, $minMax){
    usort($array, function ($a, $b) use ($optimal, $minMax) {
        // check closeness of protein to optimal
        $apo = abs($a['macros']['protein'] - $optimal['protein']);
        $bpo = abs($b['macros']['protein'] - $optimal['protein']);
        // if not equally close, return the closest
        if ($apo != $bpo) return $apo <=> $bpo;
        // same protein difference to optimal, return the one with least carbs
        return $a['macros']['carb'] <=> $b['macros']['carb'];
    });
    return $array;
}

For your sample data this returns:

Array
(
    [0] => Array
        (
            [id] => 200
            [macros] => Array
                (
                    [calorie] => 443.21
                    [fat] => 35.95
                    [carb] => 3.86
                    [protein] => 24.3
                )
        )
    [1] => Array
        (
            [id] => 3
            [macros] => Array
                (
                    [calorie] => 472.07
                    [fat] => 38.4
                    [carb] => 9.46
                    [protein] => 18.25
                )
        )
    [2] => Array
        (
            [id] => 19
            [macros] => Array
                (
                    [calorie] => 455.22
                    [fat] => 42.08
                    [carb] => 5.25
                    [protein] => 15.81
                )
        )
    [3] => Array
        (
            [id] => 18
            [macros] => Array
                (
                    [calorie] => 457.73
                    [fat] => 41.92
                    [carb] => 5.61
                    [protein] => 10.94
                )
        )
    [4] => Array
        (
            [id] => 9
            [macros] => Array
                (
                    [calorie] => 445.37
                    [fat] => 41.15
                    [carb] => 9.25
                    [protein] => 10.13
                )
        )
    [5] => Array
        (
            [id] => 1
            [macros] => Array
                (
                    [calorie] => 487.98
                    [fat] => 48.79
                    [carb] => 7.35
                    [protein] => 8.06
                )
        )
)

Demo on 3v4l.org