Callbacks Vs Promises Vs Async/Await

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  MEAN Stack Developer

Introduction

Before you understand the callbacks, promises, and async/await, it is important to understand the concept of asynchronous programming. This is why because in JavaScript unlike synchronous operations that execute line by line, asynchronous operations allow the code to continue running without waiting for a task to complete. This is important for completing tasks such as fetching data from a server, handling user input, or performing time-consuming operations. Well, these Mean Stack Developer Skills are necessary to have. Because due to this they can write cleaner, maintainable, and performant code. So let’s understand Callbacks in detail.

What is Callbacks?

Callbacks are functions that are passed as an argument to other functions. They are implemented after the completion of an asynchronous operation. Well, in the beginning mode, they are good for handling asynchronous code. But more often they lead to the infamous “Callback Hell” due to nested callbacks. So it makes code difficult to read and maintain properly. Example:

JavaScript function fetch data(URL, callback) { // Simulate asynchronous operation setTimeout(() => { const data = { name: 'John Doe', age: 30 }; callback(data); }, 1000); }

fetchData('https://api.example.com/data', (data) => { console.log(data); });

Promises: A More Elegant Solution

Promises offer a more structured way through which it gets easy to handle the asynchronous operations. A promise shows the eventual completion of the asynchronous operation and its resulting value. Example:

JavaScript function fetchData(url) { return new Promise((resolve, reject) => { // Simulate asynchronous operation setTimeout(() => { const data = { name: 'John Doe', age: 30 }; resolve(data); }, 1000); }); }

fetchData('https://api.example.com/data') .then(data => console.log(data)) .catch(error => console.error(error));

Promises provide a clean structure and allow for chaining operations using .then() and .catch(). They are also efficient in handling the errors more gracefully.

Async/Await: Syntactic Sugar for Promises

Async/Await is a kind of syntactic addition to Javascript that is designed to make working with promises. Well, it allows asynchronous code to look and behave as synchronous code. For Example:

JavaScript async function fetchData(url) { try { const response = await fetch(url); const data = await response.json(); return data; } catch (error) { throw error;

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} }

fetchData('https://api.example.com/data') .then(data => console.log(data)) .catch(error => console.error(error));

When you use Async/await it improves the code readability and makes error handling more simple using try...catch blocks. And if we discuss generally, if you have done the MEAN Stack Developer Course, you can build efficient and responsive applications with asynchronous Programming.

When to Use Which?

● Callbacks are less common now. But still, they are used for simple asynchronous tasks.

● Well if we talk about the Promises, they are the preferred choice for most asynchronous operations due to their flexibility and changing capacities.

● Async/Await is used to improve the code readability and maintainability, especially when dealing with multiple asynchronous operations.

Conclusion

In the above article, we learned how Callbacks, promises, and async/await are fundamental tools for handling asynchronous operations in JavaScript. While callbacks were the initial approach, promises and async/await offers important changes in terms of code readability, error handling, and overall developer experience. As a MEAN Stack developer, having a solid grasp of these concepts is essential for building robust and scalable applications. So if you are also interested in growing your career in this field, you can enroll in the MEAN Stack Developer course. It will help you understand these fundamental tools. If you master callbacks, promises, and async/await, MEAN Stack developers can write cleaner, more maintainable, and performant code.

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