Singleton class

MyObject.php

<?php
class MyObject
{
    protected static $instance;

    protected function __construct() { }

    /**
     * Returns an instance of this class
     * (this class uses the singleton pattern)
     *
     * @return MyObject
     */
    public static function getInstance()
    {
        if (!isset(self::$instance)) {
            self::$instance = new self();
        }

        return self::$instance;
    }
}