[Android] Enum Type을 피하라?

Be aware of memory overhead

Be knowledgeable about the cost and overhead of the language and libraries you are using, and keep this information in mind when you design your app, from start to finish. Often, things on the surface that look innocuous may in fact have a large amount of overhead. Examples include:

• Enums often require more than twice as much memory as static constants. You should strictly avoid using enums on Android.
• Every class in Java (including anonymous inner classes) uses about 500 bytes of code.
• Every class instance has 12-16 bytes of RAM overhead.
• Putting a single entry into a HashMap requires the allocation of an additional entry object that takes 32 bytes (see the previous section about optimized data containers).

A few bytes here and there quickly add up—app designs that are class- or object-heavy will suffer from this overhead. That can leave you in the difficult position of looking at a heap analysis and realizing your problem is a lot of small objects using up your RAM.

https://developer.android.com/intl/ko/training/articles/memory.html#Overhead