Object Oriented Programming in PHP : Final Keyword

Final Keyword:

PHP 5 introduces the final keyword, which prevents child classes from overriding a method by prefixing the definition with final. If the class itself is being defined final then it cannot be extended.

 

Following example results in Fatal error: Cannot override final method BaseClass::moreTesting()

<?php
class BaseClass {
   public function test() {
       echo "BaseClass::test() called<br>";
   }
  
   final public function moreTesting() {
       echo "BaseClass::moreTesting() called<br>";
   }
}

class ChildClass extends BaseClass {
   public function moreTesting() {
       echo "ChildClass::moreTesting() called<br>";
   }
}
?>