import { useEffect, useState } from "react";

function App() {
  const [users, setUsers] = useState([]);

  useEffect(() => {
    fetch("http://localhost:3000/users")
      .then(res => res.json())
      .then(data => setUsers(data));
  }, []);

  return (
    <div>
      <h2>User List</h2>
      {users.map(user => (
        <p key={user.id}>{user.name}</p>
      ))}
    </div>
  );
}

export default App;

const addUser = async () => {
  await fetch("http://localhost:3000/users", {
    method: "POST",
    headers: {
      "Content-Type": "application/json"
    },
    body: JSON.stringify({ name: "Deepak" })
  });
};

await fetch("http://localhost:3000/users/1", {
  method: "PUT",
  headers: {
    "Content-Type": "application/json"
  },
  body: JSON.stringify({ name: "Updated Name" })
});

await fetch("http://localhost:3000/users/1", {
  method: "DELETE"
});

project/
├── client/ (React frontend)
│    └── src/
├── server/ (Node backend)
│    └── routes/
├── package.json

const cors = require("cors");
app.use(cors());

{
  "name": "Deepak",
  "role": "Developer",
  "age": 25
}

npm install mongoose

const mongoose = require("mongoose");

mongoose.connect("mongodb://127.0.0.1:27017/myapp")
.then(() => console.log("MongoDB Connected"))
.catch(err => console.log(err));

const userSchema = new mongoose.Schema({
  name: String,
  age: Number
});

const User = mongoose.model("User", userSchema);

app.post("/users", async (req, res) => {
  const user = new User({
    name: req.body.name,
    age: req.body.age
  });

  await user.save();
  res.json(user);
});

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

app.delete("/users/:id", async (req, res) => {
  await User.findByIdAndDelete(req.params.id);
  res.json({ message: "User deleted" });
});

app.put("/users/:id", async (req, res) => {
  const user = await User.findByIdAndUpdate(
    req.params.id,
    req.body,
    { new: true }
  );
  res.json(user);
});