<?php
/**********************
Class Example
**********************/
class Car{
	//Inconsistency with access modifiers
	var $tire_count = 4;
	public $door_count = 2;
 
	function num_of_tires(){
		//You need to explicitely use $ to assign variables but then don't use them for reference
		$string = "This " . get_class($this) . " has " . $this->tire_count . " tires";
		return $string . "<br />";
	}
}
 
$my_car = new Car();
echo $my_car->tire_count . " :: " . $my_car->door_count . "<br />";
echo $my_car->num_of_tires();
 
/**********************
Global Variable Example
**********************/
//No use of var or public
$tires = 4;
$doors = 2;
 
echo $tires . " :: " . $doors . "<br />";
//echo $this->$cat;
 
//Reference looks ugly
$reference =& $tires;
echo "Reference before: " . $reference . " || ";
$tires = 2;
echo "Reference after: " . $reference;
?>