PHP5 Namespace / Aliasing explained in a script

gistfile1.php

<?php
#@author Raj KB<[email protected]>
#ini_set('display_errors',true);
#error_reporting(E_ALL | E_STRICT);
// You cannot have above because:
// Namespace declaration statement has to be the very first statement in the script

// How to use namespace?
namespace MagePsycho\Easypathhints\Helper;

class MyClass {}

// Overridden strlen() function
function strlen($param) {
    return '*';
}
const MYCONST = 'section/group/field';


$a = new MyClass();
$b = new \MagePsycho\Easypathhints\Helper\MyClass;

$c = strlen('hi');
$c2 = \strlen('hi');

$d = namespace\MYCONST;
$e = __NAMESPACE__ . '\MYCONST';

// How to use Aliasing / Importing?
use MagePsycho\Easypathhints\Helper\MyClass; //as MyClass if no as statement
$myClass = new MyClass();

use MagePsycho\Easypathhints\Helper\MyClass as AliasClass;
$aliasClass = new AliasClass();

// Results
var_dump(
    $a,
    $b,
    $c,
    $c2,
    $d,
    $e,
    constant($e),
    $myClass,
    $aliasClass
);