| >"programs should treat any unrecognized values as if they were “Other”" Having such an "Other" value does not prevent from considering that the enum is open-ended, and it simplifies a lot all the code that has to deal with potentially invalid or unknown values (no need for a validity flag or null). That's probably why in DIS (Distributed Interactive Simulation) standard, which defines many enums, all start with OTHER, which has the value zero. In STANAGs (NATO standards), the value zero is used for NO_STATEMENT, which can also be used when the actual value is in the enum but you can't or don't need to indicate it. I remember an "architecture astronaut" who claimed that NO_STATEMENT was not a domain value, and removed it from all the enums in its application. That did not last long. That also reminds me of Philippe Khan (Bordland) having in some presentation the ellipse extend the circle, to add a radius. A scientist said he would do the other way around, and Khan replied: "This is exactly the difference between research and industry". |
My favorite question on interviews on the OOP topic. It can be correct either way or both can be wrong, so the good answer would be "It depends". When developers rush to give a specific answer, they do not demonstrate due attention to the domain and it may mean that they will assume thousand other falsehoods from those articles on Github.