<?php
class Cars
{
static $wheel_count = 4;
/* The static method, car_detail(), returns the value of the
static property, $wheel_count. */
static function car_detail()
{
/* The 'self' keyword is the same as using the '$this' pseudo-
property in order to reference a property within the confines
of the class it resides in. */
return self::$wheel_count;
}
}
class Trucks extends Cars
{
static function display()
{
/* The 'parent' keyword references the class that
the current class is extending. It can be used to
call upon a parent class's methods or properties. */
echo parent::car_detail();
}
}
Trucks::display();