Callback Functions

The video tutorial introduces callback functions, explaining their role in JavaScript as functions passed as parameters to other functions. It distinguishes between synchronous and asynchronous callbacks, using examples like setTimeout. The tutorial simulates server actions by creating and retrieving posts, highlighting issues with synchronous operations. It then demonstrates how to use callbacks to handle asynchronous tasks effectively, ensuring operations complete in the correct order. The tutorial prepares viewers for building an Ajax library in future lessons.

What is a callback function?

• A function that runs in the background without being called.

• A function that is used to handle errors in a program.

• A function that is passed as an argument to another function and executed later.

• A function that is called immediately after it is defined.

Which of the following is an example of a synchronous callback?

• Promise.then

• setTimeout

• Array.forEach

• XMLHttpRequest

In the practical example, what issue arises when creating and retrieving posts?

• The posts are duplicated in the output.

• The server crashes due to too many requests.

• The posts are not displayed in the correct order.

• The new post is not included when retrieving posts.

How does using a callback function solve the issue of asynchronous operations in the example?

• By delaying the execution of all functions.

• By ensuring the new post is created before retrieving posts.

• By running all functions simultaneously.

• By preventing any function from executing until all are ready.

What is the main advantage of using asynchronous callbacks?

• They make the code run faster.

• They allow other operations to continue while waiting for a task to complete.

• They simplify the code structure.

• They eliminate the need for error handling.

Why might callbacks be confusing for beginners?

• They require understanding of complex algorithms.

• They involve passing functions as arguments, which is a new concept for many.

• They require advanced mathematical knowledge.

• They are rarely used in real-world applications.

What will the next video focus on after understanding callbacks?

• Building a custom object-oriented Ajax library.

• Learning about synchronous programming.

• Exploring advanced JavaScript frameworks.

• Understanding error handling in JavaScript.