Examples

In this example, we first define a base class and an extension of the class. The base class describes a general vegetable, whether it is edible, and what is its color. The subclass Spinach adds a method to cook it and another to find out if it is cooked.

Example #1 Class Definitions

Vegetable

<?phpclass Vegetable {    public $edible;    public $color;    public function __construct($edible, $color = "green")    {        $this->edible = $edible;        $this->color = $color;    }    public function isEdible()    {        return $this->edible;    }    public function getColor()    {        return $this->color;    }}?>

Spinach

<?phpclass Spinach extends Vegetable {    public $cooked = false;    public function __construct()    {        parent::__construct(true, "green");    }    public function cook()    {        $this->cooked = true;    }    public function isCooked()    {        return $this->cooked;    }}?>

We then instantiate 2 objects from these classes and print out information about them, including their class parentage. We also define some utility functions, mainly to have a nice printout of the variables.

Example #2 test_script.php

<?php// register autoloader to load classesspl_autoload_register();function printProperties($obj){    foreach (get_object_vars($obj) as $prop => $val) {        echo "\t$prop = $val\n";    }}function printMethods($obj){    $arr = get_class_methods(get_class($obj));    foreach ($arr as $method) {        echo "\tfunction $method()\n";    }}function objectBelongsTo($obj, $class){    if (is_subclass_of($obj, $class)) {        echo "Object belongs to class " . get_class($obj);        echo ", a subclass of $class\n";    } else {        echo "Object does not belong to a subclass of $class\n";    }}// instantiate 2 objects$veggie = new Vegetable(true, "blue");$leafy = new Spinach();// print out information about objectsecho "veggie: CLASS " . get_class($veggie) . "\n";echo "leafy: CLASS " . get_class($leafy);echo ", PARENT " . get_parent_class($leafy) . "\n";// show veggie propertiesecho "\nveggie: Properties\n";printProperties($veggie);// and leafy methodsecho "\nleafy: Methods\n";printMethods($leafy);echo "\nParentage:\n";objectBelongsTo($leafy, Spinach::class);objectBelongsTo($leafy, Vegetable::class);?>

The above examples will output:

veggie: CLASS Vegetable
leafy: CLASS Spinach, PARENT Vegetable

veggie: Properties
        edible = 1
        color = blue

leafy: Methods
        function __construct()
        function cook()
        function isCooked()
        function isEdible()
        function getColor()

Parentage:
Object does not belong to a subclass of Spinach
Object belongs to class Spinach, a subclass of Vegetable

One important thing to note in the example above is that the object $leafy is an instance of the class Spinach which is a subclass of Vegetable.