Routing

Quick Introduction

Routing is a single PHP idea you'll use in almost every backend project.

In this lesson you learn only routing — not five topics at once. By the end you can write a small working example and explain it in an interview.

We connect each lesson to our course projects: Login System, Blog CMS, REST API, Inventory, Employee Management, and E-Commerce Backend.

Business Problem

You're building the Blog CMS. After a user signs in, you need routing working correctly before storing data or showing a dashboard.

Without understanding Routing, the team ships bugs: wrong totals, broken sessions, or type errors that only appear in production. This lesson fixes that with one clear pattern you can copy into your project today.

Core Concept

• Routing is one focused idea — learn it before mixing with other PHP topics.
• Use it in PHP 8.3+ with declare(strict_types=1); at the top of every file.
• Our course project (Blog CMS) uses routing in real handlers.
• Run small scripts with php file.php after each change — don't just read.
• Interviewers ask for a one-minute explanation plus a tiny code sample.

Syntax

Core syntax for Routing. Every keyword below appears in production PHP — Laravel and Symfony use the same primitives under the hood.

declare(strict_types=1);

Keywords: declare · strict_types · namespace

Step-by-Step Example

Run this script locally. Change one value, run again, and watch what changes.

<?php
declare(strict_types=1);

// routes/web.php — Laravel 11
use App\Http\Controllers\ProductController;
use Illuminate\Support\Facades\Route;

Route::get('/', fn () => view('welcome'));

Route::prefix('api/v1')->group(function () {
    Route::get('/products', [ProductController::class, 'index']);
    Route::get('/products/{product}', [ProductController::class, 'show'])
        ->whereNumber('product');
    Route::post('/products', [ProductController::class, 'store'])
        ->middleware('auth:sanctum');
});

Line by line

1. — part of the routing example; run the file to see the result.
2. declare(strict_types=1); — turns on strict type checking for this file.
3. use App\Http\Controllers\ProductController; — part of the routing example; run the file to see the result.
4. use Illuminate\Support\Facades\Route; — part of the routing example; run the file to see the result.
5. Route::get('/', fn () => view('welcome')); — part of the routing example; run the file to see the result.

Authenticated

Real-World Example

In the Blog CMS, routing appears in a single request handler — not spread across ten files. Keep the example small, test it with php, then paste the pattern into your project branch.

<?php
declare(strict_types=1);

// TODO: Routing exercise for Blog CMS