DAY 21

🔖 오늘 읽은 범위 : 10장 끝

<aside> 😃 책에서 기억하고 싶은 내용을 써보세요.

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• ...another key OO class design principle known as the Open-Closed Principle, or OCP. Classes should be open for extension but closed for modification.
• Needs will change, therefore code will change. We learned in OO 101 that there are concrete classes, which contain implementation details (code), and abstract classes, which represent concepts only. A client class depending upon concrete details is at risk when those details change. We can introduce interfaces and abstract classes to help isolate the impact of those details.
• The lack of coupling means that the elements of our system are better isolated from each other and from change. This isolation makes it easier to understand each element of the system.
• By minimizing coupling in this way, our classes adhere to another class design principle known as the Dependency Inversion Principle (DIP). In essence, the DIP says that our classes should depend upon abstractions, not on concrete details.

<aside> 🤔 오늘 읽은 소감은? 떠오르는 생각을 가볍게 적어보세요

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Class chapter is generally difficult for me as I never use Class. I think I understand the concept but can’t think of any personal experiences related to this.

<aside> 🔎 궁금한 내용이 있거나, 잘 이해되지 않는 내용이 있다면 적어보세요.

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<aside> 💡 소감 3줄 요약

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• It’s better to make classes not depend upon each other. Dependency Inversion Principle.
• Classes should be open for extension but closed for modification. Open-Closed Principle.