Modern JavaScript from the Beginning - Second Edition - Callback to Promise Refactor

The video tutorial explains how to handle asynchronous code in JavaScript using callbacks and promises. Initially, it describes the use of callbacks to manage asynchronous tasks, such as creating and retrieving posts. The tutorial then refactors the code to use promises, highlighting the benefits of promises over callbacks. It also covers error handling with promises, demonstrating how to use the 'catch' method to manage errors effectively. The tutorial provides a practical example of converting callback-based code to promise-based code, ensuring a better understanding of asynchronous programming in JavaScript.

What problem does using a callback solve in the post array example?

• It reduces the number of posts.

• It makes the code run faster.

• It simplifies the code structure.

• It ensures posts are added in the correct order.

What is the first step in refactoring the create post function to use a promise?

• Add a new callback function.

• Remove the callback parameter.

• Change the function to synchronous.

• Add a delay to the function.

How do you handle the result of a promise in JavaScript?

• Using a callback function.

• Using a loop.

• Using the .then method.

• Using a synchronous function.

What is the purpose of the .catch method in promises?

• To convert a promise into a callback.

• To delay the execution of a promise.

• To handle errors that occur in the promise.

• To execute code after a promise resolves.

What happens when an error is detected in the promise example?

• An error message is displayed on the page.

• The error is ignored.

• The promise is automatically resolved.

• The error is logged to the console.

Why is it important to handle errors in asynchronous operations?

• To increase the speed of execution.

• To ensure the program continues to run smoothly.

• To improve code readability.

• To reduce the number of lines of code.

What is the main takeaway regarding handling promises?

• Promises should be handled with .then and .catch methods.

• Promises are only useful for synchronous code.

• Promises should always be avoided.

• Promises are faster than callbacks.