(PHP 4, PHP 5, PHP 7)
array_unshift — Prepend one or more elements to the beginning of an array
   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 changed.
  
arrayThe input array.
...The values to prepend.
   Returns the new number of elements in the array.
  
| Version | Description | 
|---|---|
| 7.3.0 | This function can now be called with only one parameter. Formerly, at least two parameters have been required. | 
Example #1 array_unshift() example
<?php
$queue = array("orange", "banana");
array_unshift($queue, "apple", "raspberry");
print_r($queue);
?>
The above example will output:
Array
(
    [0] => apple
    [1] => raspberry
    [2] => orange
    [3] => banana
)