Dealing with questions with obvious replies

Question

I am slightly confused on how to deal with questions which cover say the following scenarios

Scenario 1

A user asks a questions and says that he is not getting the correct result. The code he is using is

Sub Sample()
    mass = 10
    MsgBox mas
End Sub

The answer here is that the user has misspelt the variable

Scenario 2

A user asks a question and says that he is getting an error Duplicate declaration in the code. What should he do to remove the error.

Sub Sample()
    Dim mass As Double
    Dim mass As Double
    mass = 10
    MsgBox mass
End Sub

The answer here is that the user should delete the duplicate line or use a different variable name.

My Question

In such cases what do we do?

1. Leave a comment
2. Answer the question explaining on what the user is doing wrong
3. Close the question as Off Topic
4. Ignore the Question

Live Example

How should I have handled THIS post? Did I handle it correctly? Or should I have handled it in a different manner?

Answer 1

Since it is no longer possible to close as off-topic "for not demonstrating minimal understanding" as suggested by @KerrekSB, I would close your two example questions as "off-topic because..." (emphasis mine)

This question was caused by a problem that can no longer be reproduced or a simple typographical error. While similar questions may be on-topic here, this one was resolved in a manner unlikely to help future readers. This can often be avoided by identifying and closely inspecting the shortest program necessary to reproduce the problem before posting.

Misspelling a variable name or duplicating a line both count as a typo in my book.

Answer 2

I would leave a comment explaining the problem, which should only take one short sentence, and vote to close as off-topic for not demonstrating minimal understanding, or a custom reason. Minimal understanding fits well enough, I think, in the sense that minimal understanding of anything includes the ability to perform basic spell checking, and of a programming language in particular it should include being able to make sense of very clear and direct error messages. Or say something to that effect in the custom off-topic reason.

It all boils down to the fact that such questions are entirely useless, as they will never, ever help anyone else, nor would anyone ever come looking for such a question. The essence of the two examples (modulo my caveat below) is that they are almost tutorial in nature: problems that someone new to a field may encounter along the way. Undoubtedly there are many people who learn a thing for the first time in their life and would love to post a question about every small detail on SO to get help, but that's now what the site is trying to be.

I consider the eventual deletion of such question a clean-up that helps to keep the site relevant.

I should add that the second example is a bit more complex. What I said applies to questions which are obviously lacking basic care and effort in narrowing down the problem. It would be a rather different situation if the poster noted the duplicate declaration error, pointed to it, said that the error went away if she removed a line, and then asked why duplicate declarations are a problem and how one could guard against those. That would be fine and well. It's the lack of basic effort in the examples which is my guide as to whether a question will be of future use.