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 declaration is the declare statement, for defining encoding of a source file. In addition, no non-PHP code may precede a namespace declaration, including extra whitespace:
Example #2 Declaring a single namespace
<html>
<?php
namespace?MyProject;?//?fatal?error?-?namespace?must?be?the?first?statement?in?the?script
?>In addition, unlike any other PHP construct, the same namespace may be defined in multiple files, allowing splitting up of a namespace's contents across the filesystem.
← Namespaces overview
Declaring sub-namespaces →
? 1997–2017 The PHP Documentation GroupLicensed under the Creative Commons Attribution License v3.0 or later.
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