Merge 2 arrays after a specific key in PHP - php

Question

I have 2 arrays:
$array["a"];
$array["b"];
$array["c"];
$array["d"];
$otherarray["otherkey"];
I want to merge it and that $otherarray["otherkey"] is right after $array["b"]
I am using array_merge($array,$otherarray) but this creates this array:
$newarray["a"];
$newarray["b"];
$newarray["c"];
$newarray["d"];
$newarray["otherkey"];
Is there a way to insert it right after ["b"] so it becomes:
$newarray["a"];
$newarray["b"];
$newarray["otherkey"];
$newarray["c"];
$newarray["d"];

Answer 1

Maybe you can try somehting like this :
// Your first array
$array["a"] = "a";
$array["b"] = "b";
$array["c"] = "c";
$array["d"] = "d";
// Your second array
$otherarray["otherkey"] = "otherkey";
// I create a function with 4 param :
// $first_array : the first array you want to merge
// $second_array : the second array you want to merge
// $merge_after_key : the key of the first array you will use to know when your merge the second array
// $otherkey : the key of the second array you will merge
function mergeArrayByKey($first_array, $second_array, $merge_after_key, $otherkey) {
// I create a new array
$new_array = array();
// Now I will loop through the first array and create the new array for each key
foreach ($first_array as $key => $value) {
$new_array[$key] = $value;
// When key of first array meet the merge after key : I know I need to add the second array to my result array
if ($key === $merge_after_key) {
$new_array[$otherkey] = $second_array[$otherkey];
}
}
// Then I return the new array
return $new_array;
}
// Now you can use it and change the value if you need.
// For your example I use your two array + the key 'b' and the 'otherkey'
$result = mergeArrayByKey($array, $otherarray, 'b', 'otherkey');
var_dump($result);
Output is :
array (size=5)
'a' => string 'a' (length=1)
'b' => string 'b' (length=1)
'otherkey' => string 'otherkey' (length=8)
'c' => string 'c' (length=1)
'd' => string 'd' (length=1)

Answer 2

This is another option:
<?php
$first = ["a" => 1, "b" => 2, "c" => 3, "d" => 4];
$second = ["inserted" => "here", "and" => "also here"];
function mergeAtKey($first, $second, $key) {
$bothParametersAreArrays = is_array($first) && is_array($second);
$requestedKeyExistsInFirstArray = array_key_exists($key, $first);
if (!($bothParametersAreArrays && $requestedKeyExistsInFirstArray)) {
throw new Exception;
}
$keyPositionInFirstArray = array_search($key, array_keys($first)) + 1;
$firstSlice = array_slice($first, 0, $keyPositionInFirstArray, true);
$secondSlice = array_slice($first, $keyPositionInFirstArray, count($first) - 1, true);
return $firstSlice + $second + $secondSlice;
}
print_r(mergeAtKey($first, $second, "b"));