spl_autoload_extensions

The order of the extensions influence the velocity of the reply. For example: spl_autoload_extensions(".php, .inc");is more fast than:spl_autoload_extensions(".inc, .php");Check out this example:Some class files:ClassA.php<?php class ClassA { var $val = 'Hello from class "ClassA"'; } ?>ClassB.php<?php class ClassB { var $val = 'Hello from class "ClassB"'; } ?>ClassC.php<?php class ClassC { var $val = 'Hello from class "ClassC"'; } ?>ClassD.php<?php class ClassD { var $val = 'Hello from class "ClassD"'; } ?>ClassE.php<?php class ClassE { var $val = 'Hello from class "ClassE"'; } ?>1. Simple:<?php// default priority: .inc .phpfor($n=65; $n<70; $n++) {    $className = 'Class'.chr($n);    spl_autoload($className);    $ins = new $className;    echo $ins->val.'<br>';}// 4.2 miliseconds?>2. Change priority:<?phpspl_autoload_extensions('.php,.inc');// new priority: .php .incfor($n=65; $n<70; $n++) {    $className = 'Class'.chr($n);    spl_autoload($className);    $ins = new $className;    echo $ins->val.'<br>';}// 1.4 miliseconds?>

Extensions doesn't have to start with a dot, spl_autload() will simply append whatever you supply to the basename. The following example will try to load "test.php" first, and "test/index.php" as well:spl_autoload_register('.php,/index.php');spl_autoload('Test');