Simple examples of class constants in PHP are explained

Class constants: A class that holds unchanged data for the duration of a run.

Defined:

const keyword

const constant NAME = constant value

Example:

Class student{       public  $stu _id;       Public  $stu _name;       Public  $stu _gender;             Const  Gender_male = ' male ';       Const  Gender_female = ' woman ';}

Class constants are not restricted by Access-qualified modifiers

Access:

Class:: Constant name

Example:

Class student{       public  $stu _id;       Public  $stu _name;       Public  $stu _gender;             Const  Gender_male = ' male ';       Const  Gender_female = ' female ';        Public function construct ($id, $name, $gender = ")       {              $this->stu_id= $id;              $this->stu_name= $name;              $this->gender= ($gender = = ")? Self::gender_male: $gender;       } }

Summary: Members that can be defined in a class: constants, static properties, non-static properties, static methods, non-static methods.

Note: $this represents the current object and always represents the object of the class where $this is located?

No, because the value of $this does not depend on the class in which the $this resides, but on the execution object (execution Environment) when the $this method is called.

The execution environment of the method in which the current method is executed in the context of the object, within the method

$this represents which object.