PHP：找不到自动加载类[关闭]

I have a problem autoloading classes in PHP.

In my index.php I write (that's the simpliest one):

function _autoload($class_name) {
  require_once $class_name . '.php';
}

$a = new Cont();

My Cont.php file is located at PROJECT_ROOT/assets/core/Contr.php;

As a result my index.php file throws a fatal error:

Fatal error: Class 'Cont' not found in /var/www/bill/index.php on line 15

It should be __autoload() seems like you missed an underscore character.

That is..

function __autoload($class_name) {
  require_once $class_name . '.php';
}

$a = new Cont();

A tip from the PHP Manual...

spl_autoload_register() provides a more flexible alternative for autoloading classes. For this reason, using __autoload() is discouraged and may be deprecated or removed in the future.

First, it's __autoload - two underscores.

Second, that technique is discouraged - spl_autoload_register is a better option.

Third, you'll probably need require_once 'assets/core/' . $class_name . '.php'; if your files are in PROJECT_ROOT/assets/core.