I wrote this to help those who will take this course in the future. I don't usually leave reviews, but I wrote this because there aren't many reviews written for this course and I think there will be many people who are struggling like me. Background for taking this course - I recently became in charge of operations and development at my company. I learned basic JavaScript from lectures at school and academies, but the JavaScript I write in practice is written in an object-oriented way, not the simple procedure-oriented way I knew, so I took this course to study. Advantages of the course 1) I learned a little more about how the JavaScript I write in practice works. 2) The examples were explained in detail so the course wasn't difficult. 3) I think I can learn it without having to review it separately just by following the repeated examples. Disadvantages of the course 1) I think the content is not enough for the price. - Of course, it is cheap, but in fact, it is divided into advanced Part 1 and Part 2, and I also referred to the preview lecture of Part 2, but in fact, I think it would have been better to just combine advanced par 1 + part 2. 2) I think the lecture has too much theory. - I know that theory is important. However, for those who have already studied the basics of JavaScript, there was a lot of knowledge that they already knew. I think students who are taking advanced classes already know the basic theory, and I wish there were more practical exercises using it, and methods of writing in practice. 3) Lack of reflection of the latest trends - I purchased it directly and took the course in June 2022. I don't know when the lecture was made, but I think JavaScript has changed a lot as of now. For example, there are various JavaScript techniques such as let, const, scope, hoisting, promise, callback function, etc., but I think it would have been better if the previously explained theory class had been simple and explained the principles required for advanced JavaScript techniques. 4) Repetition of the same example - The example of creating a MenuTab was good, but it felt too repetitive. I think it would have been better if I could have learned how to write more diversely through other examples. Conclusion - I would like to thank the instructor for providing such a good lecture. It was a great help to my current work, and through repetition, I naturally learned how to design and write JavaScript classes. I think it is a good lecture to listen to at least once before going into practice. However, if you only know the basic knowledge of JavaScript and the concepts of objects, functions, and prototypes, I think you don't necessarily have to listen to this lecture. I think there are plenty of examples that follow the trend on YouTube, books, and the Internet. Still, I think it will be a great help to those who are studying JavaScript for the first time. I wrote this without any particular order, but I hope it will be helpful to the students. I wrote my personal opinions. Of course, since everyone has different opinions, you may think my writing is not very good, but I tried to write it as honestly as I could. I hope all the students will have only good things.