I followed a YouTube tutorial where the presenter explains how to make a game that runs in a web browser. The video showed him typing (and explaining) the code. I copied several lines of code. I have made bug fixes and enhancements. I'm wondering if I can show my code online, for example on GitHub? The YouTube tutorial made no indication of licensing.
As a practical matter I would have no issue if the other contacted me and told me to take it down. Also I found other people who have posted the code they made from following the video online.