Setting up first node.js project

Installing Node.js .

So let's see how to setup your first node.js project , i will explain it in very simple simple step how to do every think , what first and what second and how to do , means everything i will explain what to do when you want to setup first time backend with node.js.

Before discussing how to setup node.js application , prerequisite is you must have to install node in your system , if not please install first , because that is important for running node command , if not install that command throw error, so now i am assuming you have node in you system so let's start now.

So first step is that create a new folder folder for application , once folder created open folder in terminal , where run you first command for node.js application , below is command .

npm init -y // for skipping question and answering

npm init // give answer why you create this project

After this command ,you can see new file create with the name pakage.json in you folder, where your all project dependencies and dev dependencies stored.
This is basic initialization , your application need more packages means dependencies for example express.js, creating a Rest full API's, so let's see in next section how to do that.

Checking installation using terminal .

Meaning of this line means , as above i told use terminal to install package , there you can see installation process , given command installed package or not , it is failed or succeed to install package . let's see how it is word.
Again above i told you use express.js for creating API's so let's install express.js package via terminal. below you can see how it is works.

// Command paste in terminal.

npm install express // download latest version.

npm install express@version // download specific version .

See in picture how terminal work when you run any command , how they show status to you , given command package install or not.

Understanding Node REPL .

Built in command , read your code line by line and run accordingly, it is very useful because some time we need when i write some line of code my system automatically read that line and execute it , do not write any running command , automatically code run and execute , if it is good move ahead , if error occur then i know where is the error and then resolve it .
so you can see it is very important because you don't need to run every time to check is my code work fine perfectly , they automatically run code and show you how's the code you write . So it is very important and useful , automatically listen and execute it .

REPL :-

R :- Read.

E :- Eval.

P :- Print.

L :- Listen.

Creating first JS file .

To create first file in node.js , you have to option , before discussing that let's discuss first why we need that first file , in this first file usually we setup a server and listen them at specific port .

First approach we have direct create a file at root in the folder , usually first file name index , otherwise server . because i told you what we do there.

Second approach create a file inside src folder means source folder , where your all own code present . At src folder root create that file , why this approach because some time we need separation that's why

Running Scripts using node command .

Scripts means in your project lot's of functionality add after some time , example database , server run command , server build command so how to check everything is work or not , for example do manually in terminal first write command and then file name which one you wanted to run and check it is work or not.
But is create a overhead means every time you run command with file name, this is not a standard approach , to solve these kind of problem we write some script command in package.json file , if we want to run some particular command write that command in first package.json and then run that command or check it is work or not .

so below i am giving to you a basic script command then you will understand it what i want to say .

  "scripts": {
    "start": "node dist/index.js", 
    "dev": "tsc-watch --onSuccess \"node dist/index.js\"",
    "studio": "drizzle-kit studio",
    "db:generate": "drizzle-kit generate",
    "db:migrate": "drizzle-kit migrate"
  },

Writing Hello World Server .

Below is a Hello world server create using express.js , it's very simple i am creating this with following above strategy as discussed.

import express from "express";

async function main(){
    const app = express();

    app.use(express.json());

    const PORT = 3000;

    app.get('/', async (req, res) => {
        return res.status(200).json({message: 'Hello World'})
    })

    app.listen(PORT, () => {
        console.log(`Server Started at PORT : ${PORT}`)
    })

    return app;
}

main();

Code is very simple if you see it line by line , i think here no need to explain it , because it is very easy a code.

💡

So with my above explanation i hope you understand what i learn and what's my thought process on Setting Up Your First Node.js Application Step by Step.