Welcome to the world of web development! In this article, we will guide you through the process of building your first web application using Express.js.
What is Express.js?
Express.js is a popular web application framework for Node.js. It allows you to build web applications and APIs quickly and easily. Express.js provides a minimalistic and flexible set of features, while still being powerful enough for complex applications.
Setting up your development environment
Before we can start building our web application, we need to set up our development environment. Express.js requires Node.js to be installed on your machine, so make sure you have the latest version installed. You can download Node.js from the official website and follow the installation instructions provided.
Once you have Node.js installed, open your terminal or command prompt and run the following command to install Express.js globally:
$ npm install -g express
This command will install the Express.js framework globally on your machine, allowing you to use it in any project.
Creating a new Express.js project
Now that we have Express.js installed, let’s create a new project. Open your terminal or command prompt and navigate to the directory where you want to create your project. Run the following command to generate a new Express.js project:
$ express my-web-app
This will create a new directory called “my-web-app” with the basic structure of an Express.js application.
Exploring the project structure
Once the project is created, navigate into the project directory:
$ cd my-web-app
Inside the project directory, you will find various files and folders. The most important ones are:
- app.js: This is the entry point of your application. It sets up the Express.js server and defines the routes for your application.
- public: This folder is where you can put your static assets such as CSS, images, and JavaScript files.
- views: This folder contains the views of your application, which are written in a templating language such as EJS or Pug.
Starting the server
To start the Express.js server and see your web application in action, run the following command:
$ npm start
This will start the server on port 3000 by default. Open your web browser and visit http://localhost:3000 to see your application running.
Building your first route
Now that we have our server up and running, let’s build our first route. Open the app.js file and add the following code:
app.get('/', function (req, res) {
res.send('Hello, Express.js!');
});
This code defines a route for the root URL (“/”) of your application. When someone visits this URL, the server will send back the response “Hello, Express.js!”.
Save the file and refresh your web browser. You should now see the message “Hello, Express.js!” being displayed.
Conclusion
Congratulations! You have successfully built and set up your first Express.js web application. From here, you can start exploring more advanced features of Express.js, such as handling form submissions, integrating databases, and creating more complex routes.
Remember to refer to the Express.js documentation for more information and to discover all the amazing capabilities of this powerful framework. Happy coding!
