Using the get_declared_classes Function
The get_declared_classes() function will return an array that contains the names of all classes, subclasses, and predefined classes declared in your script.
<?php
include_once("class1.php");
include_once("class2.php");
$classArray = get_declared_classes();
foreach($classArray as $k => $v){
echo "<h3>$k = $v</h3>";
}
?>