I endorse everything m_goldberg has said. This site is definitely open for business for new and inexperienced Mathematica users. We have a whole page of answers to the question “What are the most common pitfalls awaiting new Mathematica users?” which deals with a lot of common issues. Supposedly “easy” questions can indeed be useful teaching moments, and we welcome questions that lend themselves to those kinds of answers. (Personally, they are the kinds of answers I most enjoy writing.)
But we do expect that site users, beginners or otherwise, make some effort in their questions, for example by posting the code that isn't working how they want, and explaining clearly what errors they are getting. We also expect that people at least try to search the documentation before posting here. Mathematica’s documentation is far from perfect, but it is quite comprehensive. We close questions that have arisen because of a simple syntax mistake or that could have been answered with a simple search of the documentation. We do this because we don’t think these kinds of questions are going to be much use to future visitors.
m_goldberg is quite right: do not post questions or answers just to thank people. That is not how this site works. Here is what you can do, though:
- If you have some (not too long) code that works but you think can be improved somehow, you are welcome to post the code, and ask “How can this be improved?”. You will need to say what you mean by “improved”, though (faster, more concise, more functional style, no
For loops etc). I think this might be what you mean by to post “only for comment”.
- If you have a nice solution to a problem, it is perfectly acceptable to answer your own question, and share your knowledge Q&A-style. For some examples of this, see a few self-answered questions that I posted here, here and here.