What is Express REST API? A Complete Guide | Simplilearn (2024)

Restful API is very popular and commonly used to create APIs for web-based applications. Express is a back-end web application framework of node js, and with the help of express, we can create an API very easily. This tutorial on Express REST API will walk you through all the topics on Express REST API.

Introduction

REST API is the standard way to send and receive data for web services.

A client sends a req which first goes to the rest API and then to the database to get or put the data after that, it will again go to the rest API and then to the client. Using an API is just like using a website in a browser, but instead of clicking on buttons, we write code to req data from the server. It's incredibly adaptable and can handle multiple types of requests

What Is REST API?

REST (Representational state transfer) is a popular architecture that is used to create web services.

API (Application Programming Interface is a code that allows two software programs to communicate with each other.

REST API is a software that allows two apps to communicate with one another over the internet and through numerous devices.

HTTP Request Types

HTTP Requests are simply messages that are sent by the client to do some tasks on the server

• GET - Get command is used to request data from the server, but mainly this method is used to read data
• PATCH - This command is used to update, change or replace the data
• POST - The post method is used to create new or to edit already existing data
• Delete - This delete command is used to delete the data completely from the server

API Using Express and Its Architecture

A request is sent by the client in the form of a JSON file, and with the help of an HTTP request which gets a patch post and delete, it will go to the server first then, the server sends back the response to the client in the form of a message to tell what happened to your request.

• Step 1: First, open your editor. Now open your terminal and write a command npm init -y

This command will create a JSON file.

• Step 2: Now we will install express for that write command

npm install express

This will install dependencies in the package.json file

• Step 3: Now we will create a new file to write all our code index.js

Write a few lines of code in the first line. We will import the express packages

• Step 4:

This app.listen will respond to the server to listen on a specific port which we have defined already as a variable 4000

• Step 5: Then we will write a second argument as a callback to tell the API is working, now lets run this code to check our API is working or node

To run this code, we will write a command node.

• Step 6: As our code is running fine, let's open our search engine and write localhost:4000, this will not run,

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• Step 7: Now we need an add the second argument here

localhost:4000/simplilearn

Our Simple API is running Successfully.

Conclusion

This article has touched on topics, what is rest API, and HTTP request types, and we also have created a simple Rest API. You can also enroll in Simplilearn's Advanced Executive Program In Cybersecurity to learn more about Cybersecurity and transform your career in 6 months. This program will help you develop expertise in defensive cybersecurity, application security, malware analysis, ethical hacking, etc.

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