It seems like a really really old lecture.. I understood up to PPT, but I was surprised when I saw the explanation while running Visual Studioㅠ Wow, it seemed like there would be spider webs, so I gave up halfway through because I thought I would never be able to finish it.. Even if I posted it on QnA, there was no answer, and I think it is not managed or updated at all. The part that I don't understand is that it seems like you directly code the string object and explain the functions of those functions, but the code is very fast and shown intermittently, so it is very ambiguous.. I went to the instructor's blog to see the code, and I posted a question on the bulletin board, but I couldn't find it, so I think the lecture materials are very poorㅠ If you finish it, your opinion about the lecture may change..? If you can handle the really..old.. lecture, unfriendly lecture materials, and the question bulletin board without answers, I recommend you take it.