OOP PHP需要类，扩展

Question

Currently I am trying to understand how OOP applies to PHP and I am having trouble with calling my class when I am getting into inheritance.

I am using the following PHP code:

require_once("init.php");

$table = new Table();
$table->draw();

$customer1 = new Customer();

Since the table class is just a plain class (not inherited) it will load correctly.

The init.php has the following PHP code:

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

Because the Customer class is inhereting the User class, the code for the Customer class is inside the User class, however the __autoload function is trying to call for the customer.class.php now.

My Customer class would look something like this:

class User
{
    private $_username;

    public function __construct($name)
    {
        $this->_username = $name;
    }

    public function getUsername()
    {
        return $this->_username;
    }
}

class Customer extends User
{
    public function __construct()
    {
        //some code here
    }
}

Cany anyone explain me please how I should call an inherited class with PHP?

Answer 1

You should only have one class per file. Your autoload will handle everything for you as long as every class is in its own file, named the same way...

Put all your Customer class code inside Customer.class.php

Answer 2

Each class should be written in its own file, exactly because of this autoload. There's no reason why class Customer must be within the same file as class User , just put it in its own file and your autoloader will handle it correctly.

Otherwise, you'll have to adopt some other naming scheme and write a more intelligent autoloader which can find classes in files with different names. (Don't do that, not really.)