Defining namespaces

Defining namespaces

(PHP 5 >= 5.3.0, PHP 7)

Although any valid PHP code can be contained within a namespace, only the following types of code are affected by namespaces: classes (including abstracts and traits), interfaces, functions and constants.

Namespaces are declared using the namespace keyword. A file containing a namespace must declare the namespace at the top of the file before any other code - with one exception: the declare keyword.

Example #1 Declaring a single namespace

<?php
namespace MyProject;

const CONNECT_OK = 1;
class Connection { /* ... */ }
function connect() { /* ... */ }

?>
The only code construct allowed before a namespace declaratio