After missing a pre-existing answer and providing a duplicate by accident, should one delete the duplicate?

Question

After missing a pre-existing answer and providing a duplicate by accident, should one delete the duplicate? This came up due to the following example:

I posted this answer to this question, not realizing the fact that essentially the same answer had been provided here. This had to do with why break statements tend to be necessary in different languages' switch syntaxes, and though I saw where several people mentioned matching multiple cases and handling them the same way, I had missed the one answer that mentioned handling case x by using code that applies only to that case, followed by code in a fall-through that matches both case x and case y.

In general I would think the most appropriate thing to do in cases like this, if no votes have been cast, is to just delete one's duplicate answer. But if the answer has been upvoted at least once, which kind of response would be more appropriate on Stack Exchange sites:

1. Just leave it and keep the upvote. It's not the end of the world.
2. Delete it immediately.
3. If one doesn't have the disciplined badge already, they should see if they get two more upvotes, then delete the answer and game the badge.

Answer 1

Stack Exchange is about getting the best answer to the question so having competing answers is not, in itself, a bad thing. However, when those answers say basically the same thing then the question becomes a bit more problematical to answer. Some people do flag "duplicate answers" so you do have to be careful

Some things I'd take into account if I saw one of these "duplicate answers" flags:

• If you posted your answer within a few minutes of the original then I'd be inclined to leave it alone. There's every chance you didn't see the other answer when you started yours so I'm not going to penalise you for that.
• Does your answer contain something that the other answer doesn't? Even if it's just a sentence or a link to an external reference that's enough to make it different.
• If you posted your answer hours, days or even months after the original answer then I would be inclined to delete your answer. You really should have seen the original one before posting yours.

So, if you think your answer satisfies either (or both) of the first two bullet points, leave it be. If it doesn't or it comes under the third then delete.