QUIZGUM

Coding Class

Quizgum : constants in class

Constants in Class

I can declare constants that are used in that class.
To declare a constant, use the const keyword. Constants are declared in uppercase letters. Of course it's a promise.

How to declare a constant in a class

  1. const constant name = value;

How constants are used in class

  1. self::constant name;

So let's declare and use a constant

  1. <?php
  2.     class Car
  3.     {
  4.         const TRUNK = true;
  5.  
  6.         public function checkTrunk()
  7.         {
  8.             return self::TRUNK;
  9.         }
  10.     }
  11.  
  12.     $car = new Car;
  13.     if($car->checkTrunk() == true){
  14.         echo "This car has a trunk." ;
  15.     } else {
  16.         echo "This car has no trunk." ;
  17.     }
  18. ?>

Result

To use a constant from a class outside the class, use instance ::.

How To Use constant in class

  1. Instance :: constant name;
  1. <?php
  2.     class Car
  3.     {
  4.         const TRUNK = true;
  5.  
  6.         public function checkTrunk()
  7.         {
  8.             return self::TRUNK;
  9.         }
  10.     }
  11.  
  12.     $car = new Car;
  13.     if($car::TRUNK == true){
  14.         echo "This car has a trunk.";
  15.     } else {
  16.         echo "This car has no trunk.";
  17.     }
  18. ?>

Of course, you must declare an instance so that you can use class constants outside the class.