Since it's in the name, you'd be right to assume that single-line comments only apply to one line of code. If you want multi-line comments, you'll need to use a backslash and an asterisk as opening and closing characters around the comment text:
/* this is a
multi-line comment */
You can also comment and uncomment blocks of code by highlighting them and using the command + ? shortcut on macOS and Ctrl + K + C on Windows.
Seeing example comments is good, but putting them in your code is always better. It's never too early to start commenting!
