PHP/Class/Class Inheritance

Class inheritance in action

   <source lang="html4strict">

<?php class AbstractClass {

   function abstractFunction() {
       die( "AbstractClass::abstractFunction() is abstract\n" );
   }

} class ConcreteClass extends AbstractClass {} $test = new ConcreteClass(); $test->abstractFunction();

      </source>
   
  

Create two child classes

   <source lang="html4strict">

<?php

 class vehicle{
     var $brand_name;
     var $number_of_wheels;
     var $seating_capacity;
 }
 class car extends vehicle {
     var $doors;
     var $prooftype;
     var $powersteering;
     var $powerwindows;
 }
 class motorbike extends vehicle {
     var $engine;
 }
 $merk= new car;
 $dukat=new motorbike;

?>

      </source>
   
  

Improved Inheritance: call parent constructor

   <source lang="html4strict">
 

<?php

    class shape
    {
         var $x;
         var $y;
  
         function shape($x, $y)  {
              $this->move_to($x, $y);
              print("Shape constructor called 
");
         }
         function get_x()  {
              return $this->x;
         }
         function get_y()  {
              return $this->y;
         }
         function set_x($x)  {
              $this->x = $x;
         }
         function set_y($y)  {
              $this->y = $y;
         }
         function move_to($x, $y)  {
              $this->x = $x;
              $this->y = $y;
         }
         function print_data()  {
              print("Shape is currently at " . $this->get_x() . ":" .
                                               $this->get_y() . "
");
         }
         function draw()
         {}
    }
    class rectangle extends shape
    {
         function rectangle($x, $y)  {
              parent::shape($x, $y);
         }
         function draw()  {
              print("Drawing rectangle at " . $this->x . ":" .
                                              $this->y . "
");
         }
         function print_data()  {
              print("Rectangle currently at " . $this->get_x() . ":" .
                                                $this->get_y() . "
");
         }
    }
    $rect1 = new rectangle(100, 100);
    $rect1->draw();
    $rect1->print_data();

?>

      </source>
   
  

Inheriting a Shape Class

   <source lang="html4strict">

<?php

    class shape {
         var $x;
         var $y;
  
         function shape()  {
              print("Shape constructor called 
");
         }
         function get_x()  {
              return $this->x;
         }
         function get_y()  {
              return $this->y;
         }
         function set_x($x)  {
              $this->x = $x;
         }
         function set_y($y)  {
              $this->y = $y;
         }
         function move_to($x, $y)  {
              $this->x = $x;
              $this->y = $y;
         }
         function print_data()  {
              print("Shape is currently at " . $this->get_x() . ":" .
                                               $this->get_y() . "
");
         }
         function draw()
         {}
    }
    class rectangle extends shape
    {
         function rectangle($x, $y)  {
              $this->move_to($x, $y);
         }
         function draw()  {
              print("Drawing rectangle at " . $this->x . ":" .
                                              $this->y . "
");
         }
         function print_data()  {
              print("Rectangle currently at " . $this->get_x() . ":" .
                                                $this->get_y() . "
");
         }
    }
    
    
    $rect1 = new rectangle(100, 100);
    $rect1->draw();
    $rect1->print_data();

?>

      </source>