Getting instance of an class via static function.

instanceByStaticFunction.php

<?php

class SampleClass
{
	static private $instance;

	/**
	 * This implements the 'singleton' design pattern
	 */
	static function getInstance()
	{
		if (!self::$instance) {
			self::$instance = new SampleClass();
		}

		return self::$instance;
	}

	/**
	 * Private constructor
	 */
	private function __construct()
	{
		/* ... */
	}

	/* ... */
}

?>