在 Java 使用 `enum` 這個 keyword 來宣告即可。從 Java Bytecode 可以發現，其實 `enum` 底層本身是個 `final class`, 也因此 `enum ...

Enumeration is used to retrieve or traverse all the elements of particular collection of objects. Its not considered for collections but we can use it for legacy like ...

An enum type in Java is a special data type that is defined whenever you need to define a variable with a set of predefined values such as Days of the Week, Months of the Year, items in a menu, etc.

This class has map keys and values. Any non-null object can be key or value This is very similar with HashMap except it is synchronized (ToDo) Differences between Hashtable and HashMap This project ...

Abstract: Java 1.5 introduces several new features that offer significant improvements over older Java technology. In this paper we consider the new enum construct, which provides language support for ...

Executives at IBM Think want to use AI to remove friction for their people in the mid-to-long term, but understand significant ...