Skip to main content

Final Keyword in PHP

Final method:

 A final method is a method that cannot be overridden.
To declare a method as final, you need to prefix the function name with the ‘final’ keyword.

eg: class Teacher {
   final public function attendance() {
      echo "Teacher attendance called";
   }
}

class Student extends Teacher {
   //this will cause Compile error
   public function attendance() {
       echo "Student attendance called";
   }
}

$st = new Student();
$st->attendance();

Results in Fatal error: Cannot override final method Teacher::attendance()

final class:

 A final class is a class that cannot be extended. To declare a class as final, you need to prefix the ‘class’ keyword with ‘final’. Example below.

final class Teacher {
   public function attendance() {
      echo "Teacher attendance called";
   }
}

//this will cause Compile error
class Student extends Teacher {

}

$c = new Student();
$c->attendance();
Results in Fatal error: Class ChildClass may not inherit from final class (Teacher)
Labels:

Comments

Post a Comment

Popular posts from this blog

Generate XML file in Cakephp

Steps to Generate XML file using CakePHP: Step-1 Enable to parse xml extension in config route.php file.     Router::parseExtensions('xml'); Step-2 Add Request Handler Component to the Controller    var $components = array(‘RequestHandler’); Step-3 Add controller Action For XML Generation in Post Controller     function generateXMLFile()     {         if ($this->RequestHandler->isXml()) { // check request type             $this->layout = 'empty'; // create an empty layout in app/views/layouts/empty.ctp              }        }  Add header code in empty layout <?php header('Content-type: text/xml');?> <?php echo $this->Xml->header(); ?> <?php echo $content_for_layout; ?> Step-4 Set up View To generate XML Create xml folder inside Posts vi...
53 comments
Read more

Simple JavaScript Object and Class Examples

In JavaScript, most things are objects. An object is a collection of related data and/or functionality Namespace: Everything you create in JavaScript is by default global. In JavaScript namespace is Global object . How to create a namespace in JavaScript? Create one global object, and all variables, methods, and functions become properties of that object. Example:  // global namespace var MYAPP = MYAPP || {}; Explaination: Here we first checked whether MYAPP is already defined.If yes, then use the existing MYAPP global object, otherwise create an empty object called MYAPP How to create sub namespaces? // sub namespace MYAPP.event = {}; Class JavaScript is a prototype-based language and contains no class statement.JavaScript classes create simple objects and deal with inheritance. Example: var Person = function () {}; Explaination: Here we define a new class called Person with an empty constructor. Use the class keyword class Calculation {}; A class expr...
27 comments
Read more

How to Add Next Previous links to The Event Calendar

Add Next/Previous links to The Event Calendar Wordpress Plugin Add code to your child theme’s functions.php file /**  * Allows visitors to page forward/backwards in any direction within month view */ if ( class_exists( 'Tribe__Events__Main' ) ) { class ContinualMonthViewPagination {     public function __construct() {         add_filter( 'tribe_events_the_next_month_link', array( $this, 'next_month' ) );         add_filter( 'tribe_events_the_previous_month_link', array( $this, 'previous_month' ) );     }     public function next_month() {         $url = tribe_get_next_month_link();         $text = tribe_get_next_month_text();         $date = Tribe__Events__Main::instance()->nextMonth( tribe_get_month_view_date() );         return '<a data-month="' . $date . '" href="' . $url . '" rel="next"...
24 comments
Read more