PHP example tutorial PHP automatic loading class usage example analysis

The example in this article describes the usage of PHP automatic loading class. Share it with everyone for your reference, the details are as follows:

<?php
//function __autoload($class_name) {
//  require_once $class_name . '.php';
//}
spl_autoload_register(array("core",'autoload'));//当实例化类的时候,自动调用core类中的autoload()方法来载入类
//也可以使用__autoload()来实现,但是php新版本建议使用spl_autoload_register,因为__autoload()会被逐渐废弃掉
$obj = new MyClass1();
$obj2 = new MyClass2();
class core
{
  public static function autoload($class) {
    require $class.'.php';
  }
}

Understanding the idea is the most important thing:

Automatic loading of objects

Many developers create a PHP source file for the definition of each class when writing object-oriented applications . A big annoyance is having to write a long list of include files (one file per class) at the beginning of each script.

In PHP 5, this is no longer necessary. It is possible to define an __autoload() function that is automatically called when an attempt is made to use a class that has not yet been defined. By calling this function, the scripting engine has a last chance to load the required classes before PHP fails with an error.

Tip

spl_autoload_register() provides a more flexible way to implement automatic loading of classes. Therefore, use of the __autoload() function is no longer recommended and may be deprecated in a future version.

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