PHP Class Constants: Define and Use Constants in OOP with Examples

Tutorial

Forum

PHP

PHP Basic Tutorial

Modify Strings

Concatenate Strings

Slicing Strings

Escape Characters

PHP If...Else...Elseif

PHP If...Else

PHP Shorthand If

PHP Nested If

PHP Switch

PHP Loops

While Loop

Do While Loop

For Loop

Foreach Loop

Indexed Arrays

Associative Arrays

Create Arrays

Access Arrays

Update Array Items

Add Array Items

Remove Array Items

Sorting Arrays

Multidimensional Arrays

Array Functions

PHP Forms

MySQL Connection

PHP Advanced

PHP File Create/Write

PHP OOP

PHP Static Properties

PHP Interview

PHP OOP - Class Constants

❮ Previous

Next ❯

PHP - Class Constants

Class constants in PHP are fixed values that cannot be changed once they are defined.

Class constants are case-sensitive. However, it is recommended to name the constants in all uppercase letters.

Key Features of Class Constants:

Declared using const inside a class.
Cannot be changed after declaration.
Do not use the $ symbol.
Accessed using ClassName::CONSTANT_NAME.
Can be inherited but cannot be overridden.

Syntax

class ClassName {
  const CONSTANT_NAME = value;
}

Defining and Accessing Class Constants

Example

<?php

class Car {

const WHEELS = 4; // Defining a constant

}

// Accessing the constant using the class name

echo "A car has " . Car::WHEELS . " wheels.<br>";

Try it yourself

Or, we can access a constant from inside the class by using the self keyword followed by the scope resolution operator (::) followed by the constant name, like here:

Example

<?php

class Car {

const WHEELS = 4; // Defining a constant

public function getWheels() {

return "This car has " . self::WHEELS . " wheels.";

}

// Accessing the constant using the class name

echo "A car has " . Car::WHEELS . " wheels.<br>";

// Accessing the constant using `self::` inside the class

$myCar = new Car();

echo $myCar->getWheels();

Try it yourself

❮ Previous

Next ❯

Whereisstuff is simple learing platform for beginer to advance level to improve there skills in technologies.we will provide all material free of cost.you can write a code in runkit workspace and we provide some extrac features also, you agree to have read and accepted our terms of use, cookie and privacy policy.