How to merge array using UUID value - php

Question

I have the following code :
<?php
$arr1 = array();
$arr1[] = ['UUID' => '123a-123a', 'name' => 'A1'];
$arr1[] = ['UUID' => '123b-123b', 'name' => 'B1'];
$arr1[] = ['UUID' => '123c-123c', 'name' => 'C1'];
$arr2 = array();
$arr2[] = ['UUID' => '123a-123a', 'name' => 'A2'];
$arr2[] = ['UUID' => '123b-123b', 'name' => 'B2'];
$arr2[] = ['UUID' => '123c-123c', 'name' => 'C2'];
$new_arr1 = array();
foreach ($arr1 as $key => $value) {
if(isset($new_arr1[$value['UUID']])){
$new_arr1[$value['UUID']] += ['name_a' => $value['name']];
}else{
$new_arr1[$value['UUID']] = ['name_a' => $value['name']];
}
}
$new_arr2 = array();
foreach ($arr2 as $key => $value) {
if(isset($new_arr2[$value['UUID']])){
$new_arr2[$value['UUID']] += ['name_1' => $value['name']];
}else{
$new_arr2[$value['UUID']] = ['name_2' => $value['name']];
}
}
$final_array = array_combine($new_arr1, $new_arr2);
var_dump($final_array);
Which give me the following error :
Warning: Array to string conversion in /home/user/scripts/code.php on line 32
Snippet :
https://sandbox.onlinephpfunctions.com/c/cf5fd
I want to use the UUID as an array id.
here is the expected output :
Array
(
[123a-123a] => Array
(
[name_1] => A1
[name_2] => A2
)
[123b-123b] => Array
(
[name_1] => B1
[name_2] => B2
)
[123c-123c] => Array
(
[name_1] => C1
[name_2] => C2
)
)

Answer 1

Instead of use array_combine you need to use array_merge_recursive because is multidimensional
Snippet:
https://sandbox.onlinephpfunctions.com/c/eae35
Reference:
array_merge_recursive

Answer 2

No array_combine nor intermediate arrays needed, just construct new array from those you already have:
$arr1 = array();
$arr1[] = ['UUID' => '123a-123a', 'name' => 'A1'];
$arr1[] = ['UUID' => '123b-123b', 'name' => 'B1'];
$arr1[] = ['UUID' => '123c-123c', 'name' => 'C1'];
$arr2 = array();
$arr2[] = ['UUID' => '123a-123a', 'name' => 'A2'];
$arr2[] = ['UUID' => '123b-123b', 'name' => 'B2'];
$arr2[] = ['UUID' => '123c-123c', 'name' => 'C2'];
$final_array = [];
foreach( array_merge($arr1, $arr2) as $entry ){
if( empty( $final_array[$entry['UUID']] ) )
$final_array[$entry['UUID']] = ['name_1' => $entry['name']];
else
$final_array[$entry['UUID']][ 'name_' . (count( $final_array[$entry['UUID']] ) + 1) ] = $entry['name'];
}
print_r($final_array);

Answer 3

array_combine creates an array by using one array for keys and another for its values. In your case, each of the 2 arrays have individual subarrays in them. Hence the error when it tries to make one of the subarrays as a string(which it can't).
In your code, you can use a single $new_arr and the make the code more concise with the null coalescing operator(??) like below:
<?php
$new_arr = array();
foreach (array_merge($arr1,$arr2) as $key => $value) {
$new_arr[$value['UUID']] = $new_arr[$value['UUID']] ?? [];
$new_arr[$value['UUID']] += [('name_' . (count($new_arr[$value['UUID']]) + 1)) => $value['name']];
}
print_r($new_arr);
Online Demo