Namespaces in PHP
Today we are going to learn about Namespace in PHP. Let’s start with definition of namespace So “Namespace are basically a way of organising your PHP classes and preventing from any kind of code conflicts . See this example ,
<?php
namespace Webkul;
//We have here a namespace with name Webkul and a class Name Opencart
class Opencart {
//Your all code will be here for this class
}
In this example we have created a class called Opencart inside of the Webkul namespace. If we did not create namespace for class and we have another class with the same name of ‘Opencart’ included in this file we would get an error stating we cannot re-declare class. Namespace will allow us to create two class name with same name and we can include both in same file.So we can create another class with same name like this-
<?php
namespace Demo;
//We have here a namespace with name Demo and a class Name Opencart
class Opencart {
//Your all code will be here for this class
}
Here we have created same class Opencart in another namespace Demo .Now we can include both file in our application and easily we can differentiate and use both class Opencart from both namespace. As i have given a example how we can use both class in same file
<?php // include both of our Opencart classes require "Demo/Opencart.php"; require "Webkul/Opencart.php"; // create a new instance for Opencart in the Demo namespace $Opencart1 = new Demo\Opencart(); // create a new instance for Opencart in the Webkul namespace $Opencart2 = new Webkul\Opencart();
Both of these classes are different from each other and also have different code , different functionality . But here we are using both and namespace allow us to use same class name and differentiate them by there namespaces. Also we can make these code more readable by using PHP use function. For example, let’s say we want to just use Opencart in place of Demo\Opencart. Then by using PHP use function we can do like this
<?php require "Demo/Opencart.php"; require "Webkul/Opencart.php"; // included both of our Opencart classes use Demo\Opencart as Opencart; //this is to tell our code that i will use Opencart in place of Demo/Opencart //Now use of Opencart for Demo namespace $Opencart1 = new Opencart();
We have used use PHP function to tell our code that i want use Opencart in place of writing Demo/Opencart. Now also we can use another namespace class for that we have to do like this .
//This will change the Opencart class from demo to webkul namespace use Webkul\Opencart as Opencart; // Now if you will create a instance for opencart class $Opencart2 = new Opencart(); //This is new intance of class Opencart from Webkul namespace
Now if you will use Opencart class then you are using it form Webkul namespace . and you can create instance which will belongs to Opencart class from Webkul namespace. Thats all from this blog.