Comments in code will not be executed
Start with // to the end of line, or between /* and */
$a : 3 // create var a and assign 3
or
/* this is a comment
create var a and assign 3
end of comment */
$a := 3
You can use html tags in comments.
/* <html>this is <b>a comment</b><br />
create var <b>a</b> and assign 3<br />
end of comment </html>*/
$a := 3