PHP Namespaces

Why namespaces?

Namespaces group related classes and prevent name clashes — your App\Models\User and a library's Vendor\Auth\User can coexist.

<?php
// src/Models/User.php
namespace App\Models;

final class User
{
    public function __construct(public string $name) {}
}

<?php
// src/Controllers/UserController.php
namespace App\Controllers;

use App\Models\User;
use DateTimeImmutable;          // global classes need a use (or a leading \)

final class UserController
{
    public function show(): string
    {
        $user = new User("Ada");
        return $user->name . " at " . (new DateTimeImmutable())->format("H:i");
    }
}

• The namespace usually mirrors the folder structure (PSR-4), which lets Composer autoload classes.
• use Foo\Bar as Baz; imports with an alias.
• ClassName::class gives the fully qualified name as a string.

<?php
namespace App\Models;

class User
{
    public function __construct(public string $name) {}
}

$user = new User("Ada");
echo User::class, "\n";
echo get_class($user), " named ", $user->name, "\n";
echo \strtoupper("global functions still work"), "\n";

App\Models\User
App\Models\User named Ada
GLOBAL FUNCTIONS STILL WORK