Analysis of the difference between spl_autoload_register() and __autoload() in PHP_PHP Tutorial

Regarding spl_autoload_register() and __autoload(), I believe most people will choose the former? Look at the usage of both:

Copy code The code is as follows:

//__autoload usage
function __autoload($classname)
{
$filename = "./class/".$classname.".class.php";
if (is_file($filename))
{
include $filename;
}
}

//spl_autoload_register usage
spl_autoload_register('load_class');

function load_class($classname)
{
$filename = "./class/" .$classname.".class.php";
if (is_file($filename))
{
include $filename;
}
}

The benefits of using spl_autoload_register() are indescribable:
(1) Automatically loading objects is more convenient, and many frameworks do this:

Copy code The code is as follows:

class ClassAutoloader {
public function __construct() {
spl_autoload_register(array ($this, 'loader'));
}
private function loader($className) {
echo 'Trying to load ', $className, ' via ', __METHOD__, "()n";
                       include $className . '.php'; >$obj = new Class2();



(2) You need to know that the __autoload() function can only exist once. Of course, spl_autoload_register() can register multiple functions

Copy code

The code is as follows:

function a () { include 'a.php'; } function b () { include 'b.php';

}

spl_autoload_register('a');
spl_autoload_register('b');



(3) SPL functions are rich and provide more functions, such as spl_autoload_unregister() to unregister registered functions, spl_autoload_functions() to return all registered functions, etc.

For details, please refer to the PHP Reference Manual: About the SPL function list.

Note:

If it has been implemented in your program_ _autoload function, it must be explicitly registered in the __autoload stack. Because the spl_autoload_register() function will replace the __autoload function in Zend Engine with spl_autoload() or spl_autoload_call()




Copy code

Code As follows:

/*** The __autoload method will become invalid after spl_autoload_register, because the autoload_func function pointer already points to the spl_autoload method * You can add the _autoload method to the autoload_functions list through the following method */ spl_autoload_register( '__autoload' );

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http: //www.bkjia.com/PHPjc/768124.htmlTechArticle Regarding spl_autoload_register() and __autoload(), I believe most people will choose the former? Look at the usage of the two: Copy the code The code is as follows: //__autoload usage function __autoload($clas...