If a challenge gives a set of languages to choose from, how freely can I choose a version?

Concrete example: I found a solution for a challenge in JavaScript. The challenge just lists a number of languages that are valid for that challenge, and JavaScript is one of them.

But my solution is kind of limited.

It is only working on JavaScript used in Mozilla Firefox and even they dropped support of that feature for version 12 and later. So on the one hand I agree it is nothing one really would use in any productive code. But on the other hand, technically seen, that's what JavaScript was about that time.

So would it satisfy the requirement as being JavaScript? And if not, where is the border between valid and too restricted?

  • 7
    \$\begingroup\$ Ask the challenge author, they'd be the judge in this case \$\endgroup\$
    – user45941
    Dec 8, 2015 at 13:59
  • 6
    \$\begingroup\$ If the challenge author hasn't specified any version, I'd say it's safe to use any version of the language. If the version isn't widely supported, I'd add a version number / supported environments in the answer \$\endgroup\$
    – Downgoat
    Dec 10, 2015 at 4:24

1 Answer 1


TL;DR: ask the OP.

Most challenges are open to all languages.

However to before giving an acceptance (green check mark) a responsible challenge poster (OP) should check the code themselves.

The OP may therefore post restrictions. The most common is that the language must be available free of charge. Another common restriction may be that the language must be available for the OP's operating system.

King of the Hill challenges are often significantly more restrictive, as the answer must work with the game controller.

There is nothing inherently wrong with a submission that only works in an obsolete version of Mozilla Firefox, but if the OP and others cannot verify it you may not get an acceptance.

Also: be clear in your answer that it only works in an old version of a specific browser and indicate where to obtain it. Nothing destroys your credibility like having everyone trying to run your code and failing. Saying later "oh, I forgot to mention it only works in revision X of Firefox" does little to restore it.


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