I have an old question, it has a sample of code. If I want to reference this code in my new question, how should I do ?
Should I add a link to old question in my new question or comment ?
All questions should be self-containing.
Put the code that is needed for the new question in it. Additionally you can reference the old question for context.
All questions treated individually.
If your another question requires the link to previous question you can put the link of your previous question site into the current one or you can update the question by Re posting the old code with some new features.