when answering a coding question, is it better to just answer the question, or rewrite the OP's code?

Question

For example, if the OP asks why the array arr is not full in the following code:

for (var i=0;i<10;++i) {
  var arr=new Array();
  arr[i]=i;
}

Is it better to simply say "put the arr initialisation outside the loop", or to totally rewrite the poster's code to do it for them?

The reason I ask is that it makes sense to me to just suggest an answer and have the poster learn something by figuring it out for themselves.

If you just give them the answer on a plate, they will expect that in future, possibly even asking the same question again because they didn't learn the first time.

Answer 1

I think it depends on who you are answering to.

If you can see that it is a total beginner who needs things to be explain step by step, then rewrite his code, showing and explaining to him where things can be improved.

If you have to deal with an experienced user (who is just probably too tired or something. I guess you can have an hint on his skills if you check his questions and answers), then just a simple formal explanation should be enough.

Answer 2

The obvious and simple answer is "of course it's better to just show the way".

However, things are not always that simple. The OP might not understand something like "put the arr initialisation outside the loop" - either language barrier, or lack of experience. (or both)

So in my opinion posting code is usually good idea, no matter how trivial it might look to you.

Now if you post such code:

var arr = new Array();
for (var i = 0; i < 10; ++i) {
    arr[i] = i;
}

It's not really "rewriting" the original code, just fixing the specific issue. Usually that's what I would choose, but sometimes it might be good idea to indeed rewrite the code giving the best practice, for example:

var arr = [];
for (var i = 0; i < 10; ++i) {
    arr.push(i);
}

Answer 3

Well usually I think the best thing is to rewrite the OP's code (only if it needs rewriting) and explain carefully why I have rewritten it. This is because when I was answering question I wanted an answer that worked, not an hint. Sometimes the OP isn't very skilled and even something simple like "put the arr initialization outside the loop" could confuse him so I take the array outside the loop and explain why I do it.

I don't think I'm not answering question to "teach" something (I hope to do so, but that's not the point), I answer question to solve problems.

Answer 4

It's a must to answer the question, explaining what is wrong and pointing out solutions.

Bonus points if you do the work for the OP.