🚀 Promise vs Async/Await

This project is a simple Express API that demonstrates two different ways to handle asynchronous code when working with Mongoose:

1. Promise style — .then().catch() callbacks
2. async/await style — cleaner, more readable syntax

Perfect for beginners who want to see both styles side-by-side!

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📚 What This Code Does

• Connects to MongoDB (via Mongoose)
• Defines a User schema with name and email
• Exposes API routes to:
  • Create a user
  • Get all users
• Each action is implemented twice:
  • Promise style (/users/promise)
  • async/await style (/users/async)

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✨ Example Endpoints

1. Promise Style

• Create User → POST /users/promise
• Get All Users → GET /users/promise

// Example POST body:
{
  "name": "John Doe",
  "email": "[email protected]"
}

**2. Async/Await Style

-Create User → POST /users/async -Get All Users → GET /users/async

// Example POST body:
{
  "name": "Jane Doe",
  "email": "[email protected]"
}

🧠 Understanding Promise vs Async/Await

• Promise style

User.find()
  .then(users => res.json(users))
  .catch(err => res.status(500).send(err));

-Looks like a chain of .then() and .catch()

• Can get messy if you have multiple async steps (callback hell but with nicer syntax)

• Async/Await style

try {
  const users = await User.find();
  res.json(users);
} catch (err) {
  res.status(500).send(err);
}

• Reads top-to-bottom like normal code
• Easier to follow for complex logic = Still uses Promises under the hood — await just unwraps them

🎯 Key Takeaways

• Both styles work the same — it’s all Promises behind the scenes.
• Promise style is fine for short chains, but can become harder to read.
• Async/Await makes async code look synchronous and is easier to debug.
• In production, always wrap async code in try/catch to handle errors.

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