Node.js Complete Guide 🟢

1. Introduction

Node.js is a runtime that allows JavaScript to run on the server.

console.log("Node.js running");

2. Modules

const fs = require("fs");
fs.writeFileSync("file.txt", "Hello");

3. HTTP Server

const http = require("http");

http.createServer((req,res)=>{
  res.write("Hello Server");
  res.end();
}).listen(3000);

4. Express.js

const express = require("express");
const app = express();

app.get("/", (req,res)=>{
  res.send("Hello Express");
});

app.listen(3000);

5. Routing

app.get("/user", (req,res)=>{
  res.send("User Page");
});

6. Middleware

app.use((req,res,next)=>{
  console.log("Request");
  next();
});

7. REST API

app.get("/api", (req,res)=>{
  res.json({msg:"API data"});
});

8. MongoDB

const mongoose = require("mongoose");

mongoose.connect("mongodb://localhost/test");

9. Authentication

const jwt = require("jsonwebtoken");

const token = jwt.sign({id:1}, "secret");

10. File Handling

fs.readFile("file.txt","utf8",(err,data)=>{
  console.log(data);
});