Fill gaps in new array based on different lengths arrays - php

Question

I am trying to create one array out of the two. Two arrays may be different lengths therefore the combine result should accommodate that and fill gaps with null.
My understanding is to first find a bigger array and loop over that, fill the gaps in the smaller array, and once that is done, merge it.
This is what I have done so far, but it feels very clunky, to the point I am starting to think - there must be a better way - less loops and maybe use some of the php array helpers methods ?
<?php
$result_keys = [];
$result_data = [];
$bigger = null;
$smaller = null;
$array1 = [
[
'dog' => 2,
'cat' => 3,
],
[
'dog' => 4,
'cat' => 2,
],
[
'dog' => 2,
'cat' => 3
]
];
$array2 = [
[
'bird' => 7,
],
[
'bird' => 5
]
];
// find which array is bigger
if (count($array1) >= count($array2)) {
$bigger = $array1;
$smaller = $array2;
} else {
$bigger = $array2;
$smaller = $array1;
};
// loop over bigger array
foreach ($bigger as $i => $record) {
foreach ($record as $key => $value) {
if ($i === 0) {
$result_keys[] = $key;
};
$result_data[$i][] = $value;
}
// fill gaps in smaller array
if (!isset($smaller[$i])) {
foreach ($smaller[$i-1] as $key => $value) {
$smaller[$i][$key] = null;
}
}
};
// loop over smaller array
foreach ($smaller as $i => $record) {
foreach ($record as $key => $value) {
if ($i === 0) {
$result_keys[] = $key;
};
$result_data[$i][] = $value;
}
};
var_dump($result_keys);
var_dump($result_data);
// // expected result
// $result_keys = ['dog', 'cat', 'bird'];
// $result_data = [
// [2,3,7],
// [4,2,5],
// [2,3,null]
// ];

Answer 1

My solution to your problem:
$array1 = [
[
'dog' => 2,
'cat' => 3,
],
[
'dog' => 4,
'cat' => 2,
],
[
'dog' => 2,
'cat' => 3
]
];
$array2 = [
[
'bird' => 7,
],
[
'bird' => 5
]
];
// get the number of values of the biggest array
$count = $count = count($array1) >= count($array2) ? count($array1) : count($array2);
$values = [];
$keys = [];
for ($i = 0; $i < $count; $i++) {
$a1 = $array1[$i] ?? [];
$a2 = $array2[$i] ?? [];
$keys = array_unique(array_merge($keys, array_keys($a1), array_keys($a2)));
$values[] = array_values(array_merge(array_fill_keys($keys, null), $a1, $a2));
}
print_r($keys);
print_r($values);
Results (test here):
Array
(
[0] => dog
[1] => cat
[2] => bird
)
Array
(
[0] => Array
(
[0] => 2
[1] => 3
[2] => 7
)
[1] => Array
(
[0] => 4
[1] => 2
[2] => 5
)
[2] => Array
(
[0] => 2
[1] => 3
[2] =>
)
)