Thank you so much for your valuable review, crocus 🥰 I am even happier because you seem to have recognized my intentions and sincerity. Kotlin can be coded very similarly to Java, but if you actively utilize Kotlin's unique features, you can improve maintainability with conciseness and clarity, creating much better code. I especially recorded the codes that I liked while using them in practice, so I hope they will be helpful 😄 ps. I am currently working hard on a follow-up lecture (Introduction to Kotlin Functional Programming). Since it is an introduction, I am organizing the parts that can be used very easily and without difficulty while collaborating in practice, so I would appreciate it if you look forward to it 😆