Vfrdtyky

I have these 2 array.

First array is from user input $cart:

array(3) {

  [0]=>

  array(3) {

    ["id"]=>"3"

    ["weight"]=>"20"

    ["percentage"]=>"80"

  }

  [1]=>

  array(3) {

    ["id"]=>"1"

    ["weight"]=>"50"

    ["percentage"]=>"80"

  }

  [2]=>

  array(3) {

    ["id"]=>"2"

    ["weight"]=>"40"

    ["percentage"]=>"80"

  }

}

and second array, I do a database SELECT id, stock WHERE id IN (3,1,2), resulting $db_item

array(3) {

  [0]=>

  array(2) {

    ["id"]=>"1"

    ["stock"]=>"9539.00"

  }

  [1]=>

  array(2) {

    ["id"]=>"2"

    ["stock"]=>"9468.00"

  }

  [2]=>

  array(2) {

    ["id"]=>"3"

    ["stock"]=>"9295.00"

  }

}

I want to add the stock attribute in second array to first array.
This is what I tried, and it works, but I don't think it is necessary to have foreach, array_filter, and array_column:

foreach ($cart as $key => $cart_item) {

    $item = array_filter($db_item, function($item) use ($cart_item) {

        return $item['id'] === $cart_item['id'];

    });

    $cart[$key]['stock'] = array_column($item, 'stock')[0];

}

anyone has better idea how to optimize this?

EDIT: following Mohammad's answer, I can use more attribute in second array

$keys = ;

foreach ($arr2 as $item) {

    $keys[$item['id']] = array(

        'attr1' => $item['attr1'],

        'attr2' => $item['attr2'],

        // and so on

    );

}



$newArr = array_map(function($item) use($keys){

    $item['attr1'] = $keys[$item['id']]['attr1'];

    $item['attr2'] = $keys[$item['id']]['attr2'];

    // and so on

    return $item;

}, $arr1);

EDIT2: found out that we can simplify the foreach loop with just a single line using array_column.

$keys = array_column($arr2, null, 'id');



$newArr = array_map(function($item) use($keys){

    $item['attr1'] = $keys[$item['id']]['attr1'];

    $item['attr2'] = $keys[$item['id']]['attr2'];

    // and so on

    return $item;

}, $arr1);

Use combination of array_flip() and array_column() to create array contain id and index of second array.

Then use array_map() to add new key stock to first array.

$keys = array_flip(array_column($arr2, 'id'));

$newArr = array_map(function($item) use($keys, $arr2){ 

    $item['stock'] = $arr2[$keys[$item['id']]]['stock'];

    return $item;

}, $arr1);

Check result in demo

Also you can use foreach instead of array_flip()

$keys = ;

foreach ($arr2 as $item)

    $keys[$item['id']] = $item['stock'];



$newArr = array_map(function($item) use($keys){ 

    $item['stock'] = $keys[$item['id']];

    return $item;

}, $arr1);

Check result in demo

This can help too, one array_column + one array_map :

$arr2=array_column($arr2,'stock','id');

$arr1=array_map(function($val)use($arr2){$val['stock']=$arr2[$val['id']];return $val;},$arr1);