- Variable names can only consist of alpha-numeric characters (the letters a to z and the numbers 0 to 9), underscores (
_) or a dollar sign
- Variable names cannot start with a number.
- Variable names must start with a letter, dollar sign (
$) or an underscore (
- Variable names cannot contain spaces.
- Variable names cannot contain certain reserved keywords, such as
thisand many more.
let this = "hey you" // Uncaught SyntaxError: Unexpected token 'this'