/*Note:
Two methods refer to:
1. abstract class aaa{} (Note that there are only abstract methods in aaa, no general methods)
class bbb extends aaa{} (Overwrite abstract methods in aaa in bbb)
2. interface aaa{}
class bbb implements aaa{} (Overwrite abstract methods in aaa in bbb)
*/
<?php
//abstract root class abstract root class
abstract class Shape
{
abstract function getArea(); //Define an abstract method
}
//abstract child class abstract child class
abstract class Polygon extends Shape //Polygon
{
abstract function getNumberOfSides();
}
//concrete class entity class triangle class
class Triangle extends Polygon
{
public $base;
public $height;
public function getArea() //Overwrite the calculation area method
{
return(($this->base * $this->height)/2);
}
public function getNumberOfSides() //Overwrite the edge counting method
{
return(3);
}
}
//concrete class solid class quadrilateral
class Rectangle extends Polygon
{
public $width;
public $height;
public function getArea()
{
return($this->width * $this->height);
}
public function getNumberOfSides()
{
return(4);
}
}
//concrete class solid class Circular shape
class Circle extends Shape
{
public $radius;
public function getArea()
{
return(pi() * $this->radius * $this->radius);
}
}
//concrete root class defines a color class
class Color
{
public $name;
}
$myCollection = array(); //Create a collection of shapes and put them into an array
//make a rectangle
$r = new Rectangle;
$r->width = 5;
$r->height = 7;
$myCollection[] = $r;
unset($r);
//make a triangle
$t = new Triangle;
$t->base = 4;
$t->height = 5;
$myCollection[] = $t;
unset($t);
//make a circle
$c = new Circle;
$c->radius = 3;
$myCollection[] = $c;
unset($c);
//make a color
$c = new Color;
$c->name = "blue";
$myCollection[] = $c;
unset($c);
foreach($myCollection as $s)
{
if($s instanceof Shape) print("Area: ".$s->getArea()."<br>\n"); //If $s is an instance of the Shape class
if($s instanceof Polygon) print("Sides: ".$s->getNumberOfSides()."<br>\n");
if($s instanceof Color) print("Color:".$s->name."<br>\n");
print("<br>\n");
}
?>