Constants In PHP Object Oriented Programming

ホーム
アプリ関連ニュース
技術情報
Constants In PHP Object Oriented Programming

2020年5月18日
技術情報

Today I will talk about constants which are very useful in development. Before we dive into code samples, there are a few things you have to remember.

– It is declared inside a class with the const keyword.
– They are case-sensitive. It’s better to name them all upper case letter for best practice.
– We can access them back outside of the class with this operator (::)

Let’s see a simple constant and it has been called outside of the class.

<?php
class Welcome {
  const HELLO_MSG = "Hello From Gigas!";
}

echo Welcome::HELLO_MSG;
// this will output "Hello From Gigas!"
?>

And also we can access the constant within the class like this using self keyword.

<?php
class Welcome {
  const HELLO_MSG = "Hello From Gigas!";
  public function sayHello() {
    echo self::HELLO_MSG;
  }
}

$hello = new Welcome();
$goodbye->sayHello();
// this too will output "Hello From Gigas!"
?>

By Yuuma