Namespaces

Why Namespaces Exist

Namespaces prevent class/function name collisions and help organize large codebases. They are essential in modern PHP projects, especially with Composer autoloading.

Basic Namespace Example

Namespace declarations must be at the top of the file.

<?php
namespace App\Controllers;

class ItemController {
  public function index(): void {
    echo "Items";
  }
}

Using a Namespaced Class

Use use statements to import classes. This keeps code readable.

<?php
use App\Controllers\ItemController;

$controller = new ItemController();
$controller->index();

Fully Qualified Names

You can always reference a class by its full name (starting with backslash).

<?php
$controller = new \App\Controllers\ItemController();

Production Tip

Adopt a consistent namespace structure that matches your folder structure (PSR-4). This prepares your codebase for Composer and modern frameworks.