Merge values from different arrays to one with the same key [duplicate] - php

Question

This question already has answers here:
Transposing multidimensional arrays in PHP
(12 answers)
Closed 10 months ago.
I have two arrays:
Array
(
[0] => 5
[1] => 4
)
Array
(
[0] => BMW
[1] => Ferrari
)
And I would like to have that result. Merge the values with the same key
Array
(
[0] => Array
(
[0] => 5
[1] => BMW
)
[1] => Array
(
[0] => 4
[1] => Ferrari
)
)
How could I do that? Is there any native PHP function that does this? I tried array_merge_recursive and array_merge but did not get the expected result

Answer 1

As to #splash58 comment:
You can use array-map. Here an example:
$array = [["5", "4"], ["BMW", "Ferrari"]];
$res = array_map(null, ...$array);
Now res will contain:
Array
(
[0] => Array
(
[0] => 5
[1] => BMW
)
[1] => Array
(
[0] => 4
[1] => Ferrari
)
)
If the array in 2 different var you can use:
$res= array_map(null, ["5", "4"], ["BMW", "Ferrari"]);

Answer 2

<?php
$a = array();
$a[0] = '5';
$a[1] = '4';
$b = array();
$b[0] = 'BMW';
$b[1] = 'Ferrari';
merge_by_key($a, $b);
function merge_by_key($a, $b){
$c = array();
fill_array($c,$a);
fill_array($c,$b);
print_r($c);
}
function fill_array(&$c, $a) {
foreach ($a as $key => $value){
if(isset($c[$key])) {
array_push($c[$key], $value);
} else {
$c[$key] = array($value);
}
}
}
Output:
Array
(
[0] => Array
(
[0] => 5
[1] => BMW
)
[1] => Array
(
[0] => 4
[1] => Ferrari
)
)

Answer 3

You can use array_map with null as the first argument (there is an example in the manual), to get your desired result:
<?php
$nums = [0 => 5, 1 => 4];
$cars = [0 => 'BMW', 1 => 'Ferrari'];
var_export(array_map(null, $nums, $cars));
Output:
array (
0 =>
array (
0 => 5,
1 => 'BMW',
),
1 =>
array (
0 => 4,
1 => 'Ferrari',
),
)
Note that the following input would give the same result:
$nums = ['puff' => 5, 'powder' => 4];
$cars = ['powder' => 'BMW', 'puff' => 'Ferrari'];
It is the order, not the keys, that determine the pairings in the result when using array_map as above.
To associate by key using foreach (note order of $cars):
<?php
$nums = [0 => 5, 1 => 4];
$cars = [1 => 'Ferrari', 0 => 'BMW'];
foreach($nums as $k => $num)
$result[] = [$num, $cars[$k]];
var_export($result);
Results also in the desired output.