Deduplicate - Filter even/odd numbers

[hobovsky]

From #39

1. JavaScript Array Filter

• 7kyu
• input: array of positive integers, output: even ones
• 92% with ~18.5k completions
• No pending issues
• 13 languages (but only one of them is JavaScript), no pending translations
• Published Mar 2013, author active

2. Are arrow functions odd?

• 8kyu
• input: array of positive integers, output: odd ones. Solution is expected to be some kind of a shorthand function (lambda, arrow, etc.), but it's not enforced in almost any of available languages.
• 92% with 10k completions
• 1 pending issue
• 6 languages + 1 pending translation
• Published Jul 2015, author active

3. No oddities here

• 7kyu
• input: array of positive integers, output: even ones
• 90% with 22k+ completions
• No pending issues
• 12 languages + 2 pending translations
• Published Aug 2013, author inactive

4. Filtering even numbers (Bug Fixes)

• 8kyu
• Bug fixing
• 88% with 4.3k solutions
• No pending issues
• 3 languages, no pending translations
• Published Dec 2015, author active

5. Incorrect array_remove method

• 8kyu
• Bug fixing, structural modifications to an iterated array
• 88% with 700 completions
• No pending issues
• Ruby only
• Published Mar 2016, author inactive

---

Conclusion

• Keep 3. No oddities here
• Retire 1. JavaScript Array Filter after moving following translations:
  • Move C approved translation from 1. to 3.
  • Move COBOL approved translation from 1. to 3.
• Retire 2. Are arrow functions odd? after moving following translations:
  • Move Elixir approved translation from 2. to 3.
• Keep 4. Filtering even numbers (Bug Fixes)
• Retire 5. Incorrect array_remove method after moving following translations:
  • Move Ruby translation from 5. to 4.

[hobovsky]

Kata 1. and 3. seem to be exact duplicates.
Kata 2. is almost exact duplicate of 1. and 3., but asks for odd numbers. It could be interesting if it enforced the idea of lambdas or arrow functions, but the way it is now, it may be considered very similar to 1. and 3.

Kata 4. and 5. are bug fixing kata, so I do not think they qualify as duplicates of 1., 2., and 3., and they present an interestign concept of a concurrent modification of an iterated collection. But still, I think they are not good bug fixing kata, because all a user has to do is to delete the initial, buggy solution, and rewrite it from scratch. There's no real need for debugging, testing, etc. Just rewrite everything right away and done.

[ejini6969]

IMO keep 1 or 3. But will require transfer of 2 languages (C / C++ && CFML / Prolog) for each kept one. Retire others

[Blind4Basics]

keep 3 (instead of 1, because of the title), retire all others.

[Kacarott]

Retire 1, 2, 5. Keep 3.

Regarding 4, I like the bug which is featured and so would be inclined to keep it. Although perhaps this kind of bug is already featured in another kata, I am not sure.

[EloiseRosen]

Bug fixing kata: vote for retire 5, keep 4
Non-bug-fixing kata: vote for retire 1 and 2, keep 3

[hobovsky]

Everyone seems to agree to keep 3. for the non-bug fixing kata. From the other group, no one wants to save 5.
I am still not sure what to do with 4, if there will be no more votes to retire it, I think we will keep it.