如果键值对在多维数组中匹配，如何将两个数组与平均值合并

Question

I have an array.

$arr = array(
    [
        'amenity_id' => '4277',
        'amenity_name' => 'Floor 1',
        'category_id' => '380',
        'amenity_value' => '0',
        'unit_id' => '25253',
        'unit_number' => '701',
        'dom' => '50',
        'building_id' => '423'
    ],
    [
        'amenity_id' => '4330',
        'amenity_name' => 'Floor 7',
        'category_id' => '380',
        'amenity_value' => '53',
        'unit_id' => '25253',
        'unit_number' => '701',
        'dom' => '50',
        'building_id' => '423'
    ],
    [
        'amenity_id' => '4330',
        'amenity_name' => 'Floor 7',
        'category_id' => '380',
        'amenity_value' => '53',
        'unit_id' => '25253',
        'unit_number' => '701',
        'dom' => '20',
        'building_id' => '423'
    ],
    [
        'amenity_id' => '4331',
        'amenity_name' => 'Top Floor',
        'category_id' => '380',
        'amenity_value' => '32',
        'unit_id' => '25253',
        'unit_number' => '701,',
        'dom' => '50',
        'building_id' => '423'
    ],
    [
        'amenity_id' => '4331',
        'amenity_name' => 'Top Floor',
        'category_id' => '380',
        'amenity_value' => '0',
        'unit_id' => '25253',
        'unit_number' => '701',
        'dom' => '20',
        'building_id' => '423'
    ],

);

Here, you can see that two amenities with amenity_id 4330 and 4331 are repeated. And, I want to merge those array with the same amenity id and calculate the mean value for amenity_value and dom .

Expected output:

array(
    [
        'amenity_id' => '4277',
        'amenity_name' => 'Floor 1',
        'category_id' => '380',
        'amenity_value' => '0',
        'unit_id' => '25253',
        'unit_number' => '701',
        'dom' => '50',
        'building_id' => '423'
    ],
    [
        'amenity_id' => '4330',
        'amenity_name' => 'Floor 7',
        'category_id' => '380',
        'amenity_value' => '53',//(53+53)/2
        'unit_id' => '25253',
        'unit_number' => '701',
        'dom' => '35',//(50+20)/2
        'building_id' => '423'
    ],
    [
        'amenity_id' => '4331',
        'amenity_name' => 'Top Floor',
        'category_id' => '380',
        'amenity_value' => '16', //(32+0)/2
        'unit_id' => '25253',
        'unit_number' => '701,'
        'dom' => '35',//(50+20)/2
        'building_id' => '423'
    ],

);

Note: There could be more than two items with the same amenity_id so we need to find average(mean).

Answer 1

Below code will get all the keys of similar amenities and compare it again with main array to merge according to your need. I believe this is what you're looking for.

$newValArr = $newArr = $newAmenity = [];
foreach ($arr as $key => $value) {
    if (!array_key_exists($value['amenity_id'], $newValArr)) {
        $newValArr[$value['amenity_id']] = [];
    }
    array_push( $newValArr[$value['amenity_id']], $key );
}

foreach ($newValArr as $amenityId => $arrKeys) {
    $newAmenity = $arr[$arrKeys[0]];

    if( count($arrKeys) > 1 && $newAmenity['amenity_id'] == $amenityId){
        $newAmenity['amenity_value'] = 0;
        $newAmenity['dom'] = 0;

        foreach ($arrKeys as $arrKey) {            
            $newAmenity['amenity_value'] += ($arr[$arrKey]['amenity_value'] / count($arrKeys));
            $newAmenity['dom'] += ($arr[$arrKey]['dom'] / count($arrKeys));
        }
    }
    
    array_push( $newArr, $newAmenity);
}

print_r( $newArr );