值匹配时组合2个数组

Question

So I have these arrays that is fetched from 2 different database, I would like to combine them in one array when the ['item_name'] and ['name'] is matched then getting the ['id'] from the Array2

I tried doing the in_array but since it's multi dimensional, I can't get the right output I want, I tried foreach also but I can't also get the right output or maybe I'm doing it wrong, I'm running out of idea how I could do the output I wanted.

Example Array1:

Array
(
    [0] => Array
        (
            [item_id] => 1
            [item_name] => Bag
            [Color] => Purple
        )

    [1] => Array
        (
            [item_id] => 2
            [item_name] => Pencil
            [Color] => Yellow
        )

    [2] => Array
        (
            [item_id] => 3
            [item_name] => Tumbler
            [Color] => Blue
        )

    [3] => Array
        (
            [item_id] => 4
            [item_name] => Shirt
            [Color] => Red
        )

)

Example Array2:

Array
(
    [0] => Array
        (
            [id] => 11
            [name] => Bag
        )

    [1] => Array
        (
            [id] => 22
            [name] => Pencil
        )

    [2] => Array
        (
            [id] => 33
            [name] => Tumbler
        )

    [3] => Array
        (
            [id] => 44
            [name] => Shirt
        )

    [4] => Array
        (
            [id] => 55
            [name] => Paper
        )

    [5] => Array
        (
            [id] => 66
            [name] => Chair
        )

    [6] => Array
        (
            [id] => 4
            [name] => Notebook
        )

)

So my expected output would be:

Array
(
    [0] => Array
        (
            [id] => 11
            [name] => Bag
            [Color] => Purple
        )

    [1] => Array
        (
            [id] => 22
            [name] => Pencil
            [Color] => Yellow
        )

    [2] => Array
        (
            [id] => 33
            [name] => Tumbler
            [Color] => Blue
        )

    [3] => Array
        (
            [id] => 44
            [name] => Shirt
            [Color] => Red
        )
)

Answer 1

Try by using foreach loop. Check if in foreach loop if any index value match with another array then create a new array with all those values. You can use counter here to get the value of array inside loop.

Answer 2

You can create a map with the names and the ID from the second array and then loop to modify the first one.

Consider the following code:

$a1 = array("item_id" => 1, "item_name" => "Bag", "Color" => "Purple");
$a2 = array("item_id" => 2, "item_name" => "Pencil", "Color" => "Yellow");
$a3 = array("item_id" => 3, "item_name" => "Tumbler", "Color" => "Blue");
$b1 = array("item_id" => 11, "item_name" => "Bag");
$b2 = array("item_id" => 22, "item_name" => "Pencil");
$b3 = array("item_id" => 33, "item_name" => "Tumbler");
$arr1 = array($a1, $a2, $a3);
$arr2 = array($b1, $b2, $b3);

$map = []; // here keys are names and value are the id 
foreach($arr2 as $elem)
    $map[$elem["item_name"]] = $elem["item_id"];


$ans = [];
foreach ($arr1 as $elem) {
    if (array_key_exists($elem["item_name"], $map))  {
        $elem["item_id"] = $map[$elem["item_name"]];
        $ans[] = $elem;
    }
}

echo print_r($ans);

In this way you achieve complexity of O(n) instead of O(n^2) if trying nested for-loop

Answer 3

Been trying to simplify my code earlier and I think I got it, thanks to anju and David Winder, if anyone interested how I did it, this is how:

index = 0;
foreach ($array1 as $val){
    foreach ($array2 as $val2){
        if ($val['item_id'] == $val2['id']){
            $filtered[$index]['id'] = $val2['id'];
            $filtered[$index]['name'] = $val2['name'];
            $filtered[$index]['color'] = $val['color'];
            $index++;
        }
    }
}