[Solved] PHP array merging problem

Problems encountered:
Currently there are two arrays. It is known that in the two arrays, the id in array 1 is equal to the pid in array 2. The problem is to merge the img_url in array 2 into array 1. under the corresponding id.

Finally need to achieve:

Array ( [0] => Array ( [id] => 7 [collection_id] => 1 [prize_num] => 1 [prize_name] => Instant discount of 20 yuan [total] => 10 ,**[url_img]=> /upload/business/1476342419.png** ) [1] => Array ( [id] => 8 [collection_id] => 1 [prize_num] => 2 [ prize_name] => 20% off the entire order [total] => 20,**[url_img]=> /upload/business/1476348963.jpg**)

Problem solved

<code>先跑第一个循环，在里面跑第二个循环，去第二个数组找符合条件的item
    foreach ($shopPrizeName as $key => $value) {
               foreach ($shopPImagesName as $k => $v) {
                   if($value['id'] == $v['pid'])
                   {
                       $value['img_url']    =    $v['img_url'];
                   }
               }
               $shopData[]    =    $value;
           }

           print_r($shopData);</code>

Reply content:

Problems encountered:
Currently there are two arrays. It is known that in the two arrays, the id in array 1 is equal to the pid in array 2. The problem is to merge the img_url in array 2 into array 1. under the corresponding id.

Finally need to achieve:

Array ( [0] => Array ( [id] => 7 [collection_id] => 1 [prize_num] => 1 [prize_name] => Instant discount of 20 yuan [total] => 10 ,**[url_img]=> /upload/business/1476342419.png** ) [1] => Array ( [id] => 8 [collection_id] => 1 [prize_num] => 2 [ prize_name] => 20% off the entire order [total] => 20,**[url_img]=> /upload/business/1476348963.jpg**)

Problem solved

<code>先跑第一个循环，在里面跑第二个循环，去第二个数组找符合条件的item
    foreach ($shopPrizeName as $key => $value) {
               foreach ($shopPImagesName as $k => $v) {
                   if($value['id'] == $v['pid'])
                   {
                       $value['img_url']    =    $v['img_url'];
                   }
               }
               $shopData[]    =    $value;
           }

           print_r($shopData);</code>

Seeing that you have solved it yourself, I will give you another method

<code>/**
 * 从多维数组中抽取一列'img_url'组成新数组, 并使用多维数组中的id作为key
 * 当然你也可以不用array_column自己通过foreach拼接这个数组
 */
$idImgMap = array_column($shopImageName, 'img_url', 'id'); 
foreach ($shopPrizeName as &$value) {
    $value['img_url'] = $idImgMap[$value['id']];
}</code>

The algorithm complexity of this implementation is 2O(n), and yours is O(n^2), so the performance will be better