Instantiate class outside namespace

Question

I have a class with the namespace defined:

namespace App;   
class AppSessionHandler {
    private $db;
    //...
    $this->db = Utils::ZendDB();  >>>>>> LINHA 12
}

The following error occurs:

Class 'App Utils' not found in /Class/Utils/class.AppSessionHandler.php on line 12

The class Utils is not included in any namespace.

How to instantiate it within the class AppSessionHandler?

Answer 1

For being inside the namespace App by instantiating the class Util PHP is looking for the class App\Util, which does not exist. It is necessary to specify that you actually want to use the class Util.

This can be done in two ways:

Import this class using use

<?php

namespace App;

use Utils;

class AppSessionHandler {

    private $db;

    //...

        $this->db = Utils::ZendDB();
}

Or refer to the full class name from the global scope (\):

<?php
namespace App;

class AppSessionHandler {

    private $db;

    //...

        $this->db = \Utils::ZendDB();
}

If you will use the class Util in other class methods, the first method is more efficient. In your example you are importing the class Util, but this could be a class of another namespace as Zend\Db\Connection\Utils. Use the use simplifies the next uses in the class as it will not be necessary to use the full name of the class:

<?php

namespace App;

use Zend\Db\Connection\Utils;

class AppSessionHandler {

    //...

        $this->db = Utils::ZendDB();
}

If using this class only once, the full name from the global \ already resolves. However, it is not so clear at the beginning of the class its dependency on the class Utils

More information on how to work with namespaces you can consult on documentation^en.