The array_merge_recursive() function merges one or more arrays into one array recursively. The difference between this function and array_merge() is that if two or more elements have the same key, the array_merge_recursive() function forms the value as an array. In this case, array_merge() function considers the last one.
Syntax
array_merge_recursive(arr1, arr2, arr3, …)
Parameters
arr1 − Initial array to merge
arr2 − Another array
arr3 − Another array
Return
The array_merge_recursive() function returns an array in which the elements of all arrays passed in parameters are merged.
The following is an example that merges two array with a key repeated in the second array. In this case the array_merge_recursive() function forms the value as an array.
Example
<?php
$arr1 = array("p"=>"one","q"=>"two");
$arr2 = array("q"=>"three","r"=>"four");
print_r(array_merge_recursive($arr1,$arr2));
?>
Output
Array
(
[p] => one
[q] => Array
(
[0] => two
[1] => three
)
[r] => four
)