array_unshift() prepends passed elements to the front of the array. Note that the list of elements is prepended as a whole, so that the prepended elements stay in the same order. All numerical array keys will be modified to start counting from zero while literal keys won't be touched.
Returns the new number of elements in the array.
$queue = array("orange", "banana");
array_unshift($queue, "apple", "raspberry");
The above example will output:
 => apple
 => raspberry
 => orange
 => banana