How to Build a Simple Express Application

How to Build a Simple Express Application

You will learn about the Express web framework and begin to build an Express server.

Introduction to the Express web framework

Express is a framework that is easy to use. A set of features is provided by Express.

Express has utilities that allow you to quickly and easily create an application. It can also be used for creating mobile applications.

The request to Express is passed on to the application. For example

https: Code language: JavaScript ( javascript )

Express executes a function to handle the request when it sees the route. A route handler is a function that handles a route.

Install the Express framework

You need to use the npm command to install it.

javascript is a code language.

If you use Linux, you can use the npm command.

javascript is a code language.

Create a simple Express application

The first thing to do is create a new project directory.

mkdir express-server Code language: JavaScript ( javascript )

Second, run the npm init –yes command:

The code language is javascript.

Third, create an index.js file.

const express, const app best node js course, const get, const listen, const reply, const send, const

How it works.

First, load the Express module:

The code language is javascript.

An instance of an Express app is returned by the express function.

The express function can be used to get an instance of the app.

The code language is javascript.

Define a route handler that handles the request.

Code language: javascript

The get() method has two parameters:

The route is the first thing. The site root is what this case is.

There are two parameters in the second function, request and response.

The Request and Response classes are examples. They have a lot of helpful methods for dealing with requests.

In this example, we use the send method to send a text.

Instructions to listen to the request on port 3000 are given.

Code language: javascript

The following command is used to execute the app.

node index.js Code language: JavaScript ( javascript )

The application runs successfully if you see the output.

Listen to the port 3000 The code language is javascript.

You need to double-check the code if it has any errors.

You can open the web browser and type in the URL you want to send the request for.

http: Code language: JavaScript ( javascript )

You can see the message on the web browser.

Hi there Code language: JavaScript ( javascript )

Add a new route handler to the index.js file

const express, const app, const get, const response, const response, const response, const response, const response, const response, const response, const response, const response, const response, const response, const

If you want to run the new app, you have to stop the current app.

When you navigate to the following URL:

http: Code language: JavaScript ( javascript )

you’ll see the following content:

About Code language: JavaScript ( javascript )

When you look at the source of the page, you’ll see the following.

About< /h1> Code language: JavaScript ( javascript )

Community convention

If you look at the code elsewhere, you will find parameters like this.

“/about”, (req, res),,,,,,,,,,,,,,,,,,,,,,

The req is for request and the res is for a reply. It is a community convention to save time. We will follow the next convention.

Summary

  • Express is a framework for building applications.

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