A simple PHP 5 __autoload() example

This is probably the one reason why everyone should switch to PHP 5! According to Charl it is “teh shit”. It is the __autoload() function. You define an __autoload() function and by calling this function the scripting engine is given a last chance to load the class or include the class file before PHP fails with an error.

I’ve created this very simple example to demostrate the effectiveness of the __autoload() function. In the index.php file, I define my __autoload() function and tells it to include a file with the same name as the class. In other words, my class name is oneClass() so the file which contain oneClass() is called oneclass.php

//The magical autoload function...
function __autoload($classname)
{
	 require_once $classname . '.php';
}

Now I initialize class two :

$class2 = new twoClass('Second class');

$class2->getText();

PHP will require and include the file called twoclass.php without me doing anything. Nothing funny here… Thing is within class two I initialize class one. As you can see, nowhere did I say it should be included! So withing class two it autoloads class one and initialize it.

class twoClass
{
	private $text;

	function __construct($txt)
	{
		$this->text = $txt;
	}

	function getText()
	{
		$class = new oneClass($this->text);
		$class->getText();
	}
}

w00t!!! Nifty, hey? Note that I’ve create the page second.php to demonstrate how the same would result in an error due to the fact that I did not require class one. If you’d like to check it in action, feel free to download this example here.

One Comment to "A simple PHP 5 __autoload() example"

• stii.za.net » Blog Archive » Mail & Gaurdian makes you a part of their redevelopment process said: On 02/06/2008 at 7:48 am

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Filed in: PHP by: Stii