Is ; optional ?
Jesus Mendoza23,266 Points
Ceil-Ian MaralitFront End Web Development Techdegree Graduate 19,420 Points
If you did not put ; at the end or forgot to put it, it will throw you an error. which is hard to find if you have massive lines of code. You will eventually stumble through one the courses here at treehouse that teaches you best practices of writing codes in JS.