Just to confirm, USING UNSET CAN DESTROY AN ENTIRE ARRAY. I couldn't find reference to this anywhere so I decided to write this. 

The difference between using unset and using $myarray=array(); to unset is that obviously the array will just be overwritten and will still exist.

<?php

$myarray=array("Hello","World");

echo $myarray[0].$myarray[1];

unset($myarray);
//$myarray=array();

echo $myarray[0].$myarray[1];

echo $myarray;
?>

Output with unset is:
<?
HelloWorld

Notice: Undefined offset: 0 in C:\webpages\dainsider\myarray.php on line 10

Notice: Undefined offset: 1 in C:\webpages\dainsider\myarray.php on line 10

Output with $myarray=array(); is:
?>

<?
HelloWorld

Notice: Undefined offset: 0 in C:\webpages\dainsider\myarray.php on line 10

Notice: Undefined offset: 1 in C:\webpages\dainsider\myarray.php on line 10

Array
?>