I assume you are asking how to post source code in this forum.
Look
here. A short-cut technique is to paste the lines of code (with no line numbers), select the lines of code, and then press the
# button at the top of the post-entry window.
Notice that line numbering in your post always starts from 1, so line numbers in your post are typically different than line numbers in your actual source code. Compiler messages typically indicate the relevant line number. It is very helpful if you somehow indicate which line in your post corresponds to the line indicated in the message. You can use the Preview button to see what line numbers will be seen by people reading your post.