SCJP題庫第194題

 

Given:

enum Example{ONE, TWO, THREE}

Which statement is true?

A. The expressions (ONE == ONE) and ONE.equals(ONE) are both guaranteed to be true.

B. The expression (ONE < TWO) is guaranteed to be true and ONE.compareTo(TWO) is guaranteed to be less than one.

C. The Example values cannot be used in a raw javautil.HashMap; instead, the programmer must use a java.util.EnumMap.

D. The Example values can be used in a java.util.SortedSet, but the set will NOT be sorted because enumerated types do NOT implement java.lang.Comparable.

Ans: A

解說:

The expressions (ONE == ONE) and ONE.equals(ONE) are both guaranteed to be true.