Since the first part of your question was answered, and I still can not comment, I will consider this answer to your second question:
It is usually not advisable to post frequent questions about stack overflows. Why can you ask? For situations like this. You answered half your question and accepted this answer as correct. However ... Which of the second question? What if someone decides to answer him and gives a good answer. Only one person can answer your question as the right one. And given that these ratings change the level of interaction that you might have on Stack Overflow, it would be wrong to accept one half and not the other, simply because they were provided by two different people.
If you have a question that is somehow a subset of your first, leave a comment on the answer you need to develop. i.e.: (Question 1 = "What is a class?"; Question 2 = "Why do I need such functionality?";)
If you have a question that is a fork in your first thought, create a new question. i.e.: (Question 1 = "What is a class?"; Question 2 = "What does it mean to instantiate an object?";)
If the main subject is different, you must create a new question. Otherwise, you leave a comment. But never put 2 questions in 1 unless they have the same problem / solution.
anyway ... best wishes for the old post = P