Introduction to the MERN Stack with Example Project

The MERN Stack is a powerful combination of technologies used to develop full-stack web applications. It consists of:

• MongoDB – NoSQL database
• Express.js – Backend framework
• React.js – Frontend library
• Node.js – JavaScript runtime environment

Together, these technologies provide a seamless development experience, allowing developers to build fast and scalable applications using JavaScript for both frontend and backend.

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Why Choose the MERN Stack?

1. Full JavaScript Development – Use a single programming language for frontend and backend.
2. Scalability – MongoDB allows flexible and scalable database management.
3. Component-Based UI – React simplifies UI development with reusable components.
4. Fast Performance – Node.js handles asynchronous operations efficiently.
5. Large Community Support – Extensive resources and support from developers worldwide.

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Example MERN Stack Project: A Simple To-Do App

Let's build a basic To-Do List application using the MERN stack.

1. Setting Up the Backend (Node.js + Express.js + MongoDB)

Step 1: Initialize a new project and install dependencies

mkdir mern-todo-app && cd mern-todo-app
npm init -y
npm install express mongoose cors dotenv

Step 2: Create a simple Express server (server.js)

const express = require("express");
const mongoose = require("mongoose");
const cors = require("cors");
const app = express();
app.use(cors());
app.use(express.json());

mongoose.connect("mongodb://localhost:27017/todo", {
  useNewUrlParser: true,
  useUnifiedTopology: true,
});

const todoSchema = new mongoose.Schema({ task: String });
const Todo = mongoose.model("Todo", todoSchema);

app.get("/todos", async (req, res) => {
  const todos = await Todo.find();
  res.json(todos);
});

app.post("/todos", async (req, res) => {
  const newTodo = new Todo({ task: req.body.task });
  await newTodo.save();
  res.json(newTodo);
});

app.listen(5000, () => console.log("Server running on port 5000"));

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2. Setting Up the Frontend (React.js)

Step 1: Create a React app

npx create-react-app client
cd client
npm install axios

Step 2: Fetch and display data in App.js

import React, { useEffect, useState } from "react";
import axios from "axios";

function App() {
  const [todos, setTodos] = useState([]);
  const [task, setTask] = useState("");

  useEffect(() => {
    axios.get("http://localhost:5000/todos").then((response) => {
      setTodos(response.data);
    });
  }, []);

  const addTodo = () => {
    axios.post("http://localhost:5000/todos", { task }).then((response) => {
      setTodos([...todos, response.data]);
      setTask("");
    });
  };

  return (
    <div>
      <h1>To-Do List</h1>
      <input value={task} onChange={(e) => setTask(e.target.value)} />
      <button onClick={addTodo}>Add</button>
      <ul>
        {todos.map((todo, index) => (
          <li key={index}>{todo.task}</li>
        ))}
      </ul>
    </div>
  );
}

export default App;

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Conclusion

The MERN stack is an excellent choice for full-stack development. With just JavaScript, you can build a dynamic and responsive web application. This To-Do List app is a basic example, but you can extend it with authentication, real-time updates, and more advanced features.

Start experimenting with the MERN stack and build your own amazing projects!

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Do you have any questions or want more tutorials? Let me know in the comments!