Combining 2 Arrays when value is matched - php

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

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 2

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 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++;
}
}
}