Gain insights into Express.js essentials—routing, middleware, and RESTful APIs. Learn to integrate MongoDB, JWT authentication, validation, real-time features, and logging for scalable back-end apps.

express.tar.gz

JWT_SECRET

NODE_ENV

Express App

Express code

Express code-module

Express code-silent

Express App-p4000

Express App-test

Express App-database

Express App-database-tmux

Express App-uploads

Express-mysql

Express.js is a popular Node.js framework, especially useful for building APIs and server-side apps. It’s lightweight, unopinionated, and flexible, giving you full control over how your app is structured. Whether new to backend development or ready to build production-grade services using JavaScript, Express is a great place to start.

In this course, you’ll begin with a quick review of Node.js and asynchronous JavaScript. Then, you’ll cover Express.js essentials like routing, middleware, and modular app structure. You’ll learn to build RESTful APIs, connect your app to a database, and implement JSON web tokens (JWT) authentication. You’ll also explore validation and sanitization for added security. Finally, you’ll understand templating engines, real-time features using Socket.IO, and structured logging using Winston.

After completing this course, you’ll have a solid grasp of Express.js and the confidence to build secure, scalable, production-ready backend applications from scratch.

Learn Express.js

The server stores user session data between requests.

Every request must contain all the information the server needs to process it.

The server can reuse data from previous requests to save time.

What best describes the principle of statelessness in a RESTful API?

What best describes the principle of statelessness in a RESTful API?

What is the commonly recommended format for resource names in RESTful endpoints?

What is the commonly recommended format for resource names in RESTful endpoints?

It keeps client logic cleaner by removing the need for headers.

Why is URL versioning (e.g., `/api/v1/tasks`) generally recommended for public REST APIs?

Why is URL versioning (e.g., <code>/api/v1/tasks</code>) generally recommended for public REST APIs?

Which principle ensures that a REST API can evolve and scale by hiding the complexity of back-end components from the client?

Which principle ensures that a REST API can evolve and scale by hiding the complexity of back-end components from the client?

They store data in flexible formats like documents.

They offer predefined schemas that enforce data integrity.

What is a key advantage of using NoSQL databases like MongoDB over SQL databases?

What is a key advantage of using NoSQL databases like MongoDB over SQL databases?

To automatically validate all incoming data

To prevent exposing sensitive credentials in code

Why should the MongoDB connection string be stored in an environment variable?

Why should the MongoDB connection string be stored in an environment variable?

The app immediately drops all network connections with clients.

The database connection is closed before the app exits.

What happens during a graceful shutdown in an Express.js app?

What happens during a graceful shutdown in an Express.js app?

It updates only the fields specified in the request body.

It keeps the original document and appends new fields.

It replaces the entire document with the provided data.

It removes any existing fields not included in the request body.

What does `{ overwrite: true }` do in the context of a `findByIdAndUpdate()` call in Mongoose?

What does <code>{ overwrite: true }</code> do in the context of a <code>findByIdAndUpdate()</code> call in Mongoose?

What status code is sent when a new user is successfully created using the `POST` route?

What status code is sent when a new user is successfully created using the <code>POST</code> route?

Which Mongoose method should we use to retrieve a single user document by their unique identifier?

Which Mongoose method should we use to retrieve a single user document by their unique identifier?

Validation removes unwanted characters; sanitization checks data format.

Validation checks if data meets expected criteria; sanitization cleans and standardizes the data.

Validation converts input to safe format; sanitization rejects invalid data.

There is no difference—they are two names for the same process.

What is the primary difference between validation and sanitization?

What is the primary difference between validation and sanitization?

Which `express-validator` method ensures a string does not have leading or trailing whitespace?

Which <code>express-validator</code> method ensures a string does not have leading or trailing whitespace?

It executes all validation checks on input data.

It sends a success response after validation.

It retrieves the result of validation checks performed earlier in the middleware chain.

What does the `validationResult(req)` function do?

What does the <code>validationResult(req)</code> function do?

It removes all numeric characters from input.

It converts special characters like `<`, `>`, `'` into HTML-safe representations.

Which option best describes what `escape()` does in `express-validator`?

Which option best describes what <code>escape()</code> does in <code>express-validator</code>?

The `check()` function immediately blocks the request if validation fails.

`name` is automatically filled with a default value.

A validation error with message `'Name is required'` will be returned in the result of `validationResult(req)`.

The `check` function will sanitize the `name` field automatically.

In the `express-validator` snippet below, what happens if name is missing?

```js
check('name').notEmpty().withMessage('Name is required')
```

In the <code>express-validator</code> snippet below, what happens if name is missing?
<pre><code class="language-js">check('name').notEmpty().withMessage('Name is required')
</code></pre>

Test your ability to build APIs, interact with databases, and validate user input using Express.

Course Orientation and Preparations

Getting Started with Express.js

Diving Deeper into Routing

Mastering Middleware

Building RESTful APIs and Integrating Databases

Securing Your Express Applications

Beyond APIs: UI Rendering, Real-Time Communication, and Logging in Express

DevConnector Project

Conclusion

Quiz: REST APIs, CRUD, and Data Validation