How to automatically load class files

How to automatically load class files! Currently, autoload (the code is as follows:) is there any other way to automatically load class files? Except include (specific file path) PHPcodefunction _ autoload ($ className) {if (file_exists (model. $ className .. class. php) {include_once (how does the model automatically load class files!
Currently, autoload (the code is as follows:) is there any other way to automatically load class files? Except include (specific file path)

PHP code

  function __autoload($className){if(file_exists('model/'.$className.'.class.php')){include_once('model/'.$className.'.class.php');}if(file_exists('Controller/'.$className.'.class.php')){include_once('Controller/'.$className.'.class.php');}$prefix=$GLOBALS['groupName']=='main'?'':'../';if(file_exists($prefix.'core/'.$className.'.class.php')){include_once($prefix.'core/'.$className.'.class.php');}if(file_exists($prefix.'core/Smarty-3.1.6/'.$className.'.class.php')){include_once($prefix.'core/Smarty-3.1.6/'.$className.'.class.php');}if(file_exists($prefix.'core/Smarty-3.1.6/sysplugins/'.$className.'.php')){include_once($prefix.'core/Smarty-3.1.6/sysplugins/'.$className.'.php');}}

------ Solution --------------------
Do you think this is troublesome?
In fact, it is because you put many class files, and you should use if else if or switch... case. Statement.
If you are too troublesome, you can use an array to save all the paths, for example.

PHP code

$arr = array('classPath1','classPath2','classPath3');foreach($arr as $v){  $new_path = $v.$className.'.php';  if(file_exists($new_path)){    include_once($new_path);    break;  }}