array_merge() array_merge_recursive()
This function is used to join one or more arrays into a single array. Used to merge multiple arrays in such a manner that values of one array are appended to the end of the previous array.
Syntax: array_merge($array1, $array2, $array3...); Syntax: array_merge_recursive($array1, $array2, $array3...);
If we pass a single array, it will return re-indexed as a numeric array whose index starts from zero. If we pass a single array, it will return re-indexed in a continuous manner.
BY Best Interview Question ON 07 Apr 2020

Example

Example of an array_merge() function:

$arrayFirst = array("Topics" => "Maths","Science", "Computers");
$arraySecond = array("Class-V", "Class-VI", "Section"=>"C");
$resultArray = array_merge($arrayFirst, $arraySecond);
print_r($resultArray);

Output

Array ( [Topics] => Maths [0] => Science [1] => Computers [2] => Class-V [3] => Class-VI [Section] => C )

Example of an array_merge_recursive() function with all different keys:

$a1=array("a"=>"Best", "b"=>"Interview");
$a2=array("z"=>"Question");
print_r(array_merge_recursive($a1, $a2));

Output

: Array
(
[a] => Best
[b] => Interview
[z] => Question
)