Basic route definition in Laravel - Step-by-Step Execution

Concept Flow - Basic route definition

Start Laravel app

↓

Define route in routes/web.php

↓

Laravel reads route file

↓

Match URL to route path

↓

Run route's closure

↓

Send response to browser

Laravel reads the route file, matches the URL to a defined route, runs the associated code, and sends the response.

Execution Sample

Laravel

Route::get('/', function () {
    return 'Hello, world!';
});

Defines a route for the home URL that returns a simple greeting.

Execution Table

Step	Action	URL Requested	Route Matched?	Code Run	Response Sent
1	Laravel starts and loads routes/web.php	N/A	N/A	N/A	N/A
2	User requests '/' URL	/	Yes	Closure returns 'Hello, world!'	'Hello, world!'
3	Response sent to browser	/	Yes	N/A	'Hello, world!'
4	User requests '/about' URL	/about	No	N/A	404 Not Found

💡 Execution stops after sending response or 404 if no route matches.

Variable Tracker

Variable	Start	After Step 2	After Step 4
URL Requested	N/A	/	/about
Route Matched	N/A	Yes	No
Response	N/A	'Hello, world!'	404 Not Found

Key Moments - 2 Insights

Why does Laravel return 404 for '/about' when only '/' route is defined?

Because the execution_table row 4 shows no route matched '/about', so Laravel returns 404.

What happens when the URL matches a route?

As seen in row 2, Laravel runs the closure code and sends its return value as the response.

Visual Quiz - 3 Questions

Look at the execution_table, what response is sent when the URL '/' is requested?

A 404 Not Found

B 'Hello, world!'

C Empty response

D Error message

💡 Hint

Check row 2 and 3 in the execution_table for URL '/'

At which step does Laravel decide no route matches the URL?

A Step 1

B Step 2

C Step 4

D Step 3

💡 Hint

Look at the execution_table row where URL '/about' is requested

If you add Route::get('/about', fn() => 'About page'); how would the response for '/about' change?

A It would return 'About page'

B It would still return 404 Not Found

C It would return 'Hello, world!'

D It would cause an error

💡 Hint

Adding a matching route changes Route Matched from No to Yes in variable_tracker

Concept Snapshot

Basic route definition in Laravel:
Use Route::get('path', function() { return response; });
Laravel matches URL to path, runs closure, sends response.
If no match, returns 404 Not Found.
Routes are defined in routes/web.php.
Simple and direct way to handle URLs.

Full Transcript

In Laravel, you define routes in the routes/web.php file. When a user visits a URL, Laravel reads this file to find a matching route. If it finds one, it runs the code inside the route's closure and sends the result back to the browser. If no route matches, Laravel returns a 404 Not Found error. For example, defining Route::get('/', function () { return 'Hello, world!'; }); means when the home URL '/' is requested, Laravel sends 'Hello, world!' as the response. If the user requests a URL like '/about' without a matching route, Laravel returns 404. Adding a route for '/about' changes this behavior to return the new response instead.