Java Enum.valueOf() efficiency when value does not exist

Question

Which would you consider more efficient?

The use of \'WeekDay\' is just an example:

public enum WeekDay {
    MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDA         


        

Answer 1

I know its an old post, but I believe following result will be still interesting. I run 10000000 tests to find an element in enum ENUM {FIRST, SECOND, THIRD, FOURTH, LAST} using JDK 1.8. The table below shows time required by simple loop and valueOf().

text     loop   valueOf  ratio
------------------------------
"FIRST"  121    65       186%
"LAST"   188    57       330%
"foo"    155    8958     1.7%

Conclusion - I wouldn't use valueOf() if I expect values not matching enum.