Introduction

Hello readers! Today we're continuing our journey to become back-end masters. We've learned about asynchronous programming and callbacks, and also about promises. Now, we're going to learn about a new way to handle async code called async and await. We'll learn about how it works and how it's different from callbacks and promises. By the end of this post, you'll be able to use async and await in your projects. Let's get started!

Understanding async and await

Async and await are two new keywords introduced in JavaScript, which makes it easy to handle asynchronous operations and makes your code more readable. These keywords allow you to write asynchronous code that looks similar to synchronous code, which makes it easier to read and understand.

Asynchronous code is code that runs separately from the main thread and doesn't block it. This means that while the asynchronous code is running, the main thread can continue its execution. This allows your code to be more responsive and faster.

Before the introduction of async and await, we used to handle asynchronous operations using callbacks or promises. With callbacks, we would pass a function as a parameter to another function, which would be executed when the asynchronous operation is completed. With promises, we would return a special object called a promise, which could be used to attach callbacks to handle the result of the asynchronous operation.

Async and await is a more modern way to handle asynchronous code, which makes it look more like synchronous code. This makes it easier to read and understand, as it eliminates the need for callback functions and promise chaining. Instead, you use the await keyword to pause the code execution until a promise is resolved.

For instance, consider a scenario of fetching some data from an API endpoint. With callbacks, you would pass a callback function as a parameter to the fetch method, which would be executed once the data is received. With promises, you would attach a then method to handle the data once the promise is resolved. With async and await, you would use the await keyword before the fetch method, which would pause the execution until the data is received. This makes it more readable and simpler.

Implementing async and await

Now that we have a good understanding of what async and await are and how they differ from traditional callbacks and promises, let's dive into how to implement them in our code.

The basic syntax for using async and await is very simple. To make a function asynchronous, we simply need to add the async keyword before the function declaration. Once we have an asynchronous function, we can use the await keyword inside it to pause the execution until a promise is resolved.

Simply put,

• The async keyword is used to define an asynchronous function in JavaScript. It allows you to use the await keyword inside the function to wait for promises to resolve.

• The await keyword is used inside an asynchronous function to pause the execution of the code until a promise is resolved. It makes the code look more like synchronous code, making it easier to read and understand.

async function myAsyncFunc() {
  // Wait for promise to resolve
  const data = await promise;
  // Continue execution
  console.log(data);
}

In addition to working with promises, async and await can also be used with other asynchronous operations, such as fetch(), setTimeout(), and axios requests.

async function getData() {
  const response = await fetch('https://my-api.com/data');
  const data = await response.json();
  console.log(data);
}

When using async and await, it's important to handle any errors that may occur. The try and catch blocks work the same way as with synchronous code.

async function handleData() {
  try {
    const data = await fetch('https://my-api.com/data');
    console.log(data);
  } catch (err) {
    console.error(err);
  }
}

Advantages and Disadvantages of using async and await

Advantages of using async and await:

• Makes the code more readable and easy to understand

• Eliminates the need for callback functions and promise chaining

• Allows for more precise control of the execution flow

Disadvantages of using async and await:

• Can be harder to debug compared to traditional callbacks and promises

• Not supported in older versions of JavaScript

Use cases where async and await are especially useful:

• When you need to perform multiple operations in parallel

• When you need to handle large amounts of data

This format makes it easy to read and understand and provides clear and concise information about the advantages and disadvantages of async and await, and in which cases it would be particularly useful.

Conclusion

In conclusion, we have covered the topic of async and await in JavaScript in this blog post. We have discussed what async and await are, and how they differ from traditional callbacks and promises. We have also covered how to implement and use async and await, and discussed the advantages and disadvantages of using them.

In this blog post, we have seen that async and await make handling asynchronous code more readable and easier to understand. With the proper syntax and usage, you can write asynchronous code that looks similar to synchronous code, which eliminates the need for callback functions and promise chaining.

For those who are interested in learning more about async and await, there are many great resources available online such as the official documentation, tutorials, and video courses.

Finally, I would love to hear from you! If you have any questions or feedback, please leave a comment below.

Thank you for reading and I hope you found this blog post helpful.