billsparks··on How to win the coding interviewThat particular comment (the @param) is for JSDOC. It's so that one can generate documentation for the code. http://usejsdoc.org/about-getting-started.html
billsparks··on How to win the coding interviewI don't think the part about tests and comments is meant to apply to the whiteboard coding. It's in the section about coding on a computer.