Question

If I have a System folder in the root directory containing a Database folder with a Database.php file which holds a class

class Database{
   static function Connect(){
      echo "connect";
   }
}

And I call that from an index.php which is in the root directory.

How do I make a namespace to access the class Database::Connect();
I really am struggling with namespaces.

Do I need to put namespace System\Database at the top of my Database.php file or something? Any good examples that aren’t on php.net pages?

Answer 1

Namespaces (in PHP) are really just a way of preventing naming collisions between Classes in a project. They have been used for a some time (before they were officially supported) in the form of classes named things like “Zend_Controller_Action_Helper”.
The PHP5.3 introduction of “real” namespaces really just means we can now use short, readable names in our code by “use”ing a namespace.

eg.

file: system/database.php

namespace MyProject;

class Database {
// ...
}

file public/index.php

require_once '../system/database.php';

// here we have to use the fully qualified name of the Database class,
// this is similar to the old unofficial underscore method.
$db = \MyProject\Database::connect();

file: public/index2.php

require_once '../system/database.php';
use MyProject\Database;

// here we can simply use "Database" because the "use" statement says:
// for this file we are using the "Database" class from the "MyProject" namespace
$db = Database::connect();

Namespaces are only related to directories by convention (and for autoloading) they, in an of themselves, don’t change the way classes are included and used.