Question

This is a two part question: General, and Specific.

For the general: I often find myself wondering what constitutes a viable variable name in JavaScript? I know there are certain ‘words’ that can not be used as variables in JavaScript; But I have yet to come across either a list of non-viable variable names, or a rule to apply when creating a variable name. I usually err on the side of caution and use obscure names if I am unsure.

It would be nice to know, with certainty, what can be used as a JavaScript variable, and what can not be used.

Any advice?

For the specific: I am wondering if I can use href as a variable name in my JavaScript? Is it viable, or is it reserved?

---

Afterthought: Perhaps I can extend this question to encompass JavaScript function names as well. What names are viable, and which are reserved? If the two questions are related, I will edit to ask both.

Note: I am not asking which characters can be used in a JavaScript variable; That question is already answered here.

Answer 1

You can find lists of reserved words in JavaScript.

href is certainly fine as a variable name because href is an attribute of an a tag and in no way conflicts with JavaScript naming.

If you are ever in doubt as to whether or not a variable is already in use you can always open the developer tools (F12 in most browsers), go to the console, and type in the name. In this case you’ll get:

> href
x ReferenceError: href is not defined

Nothing is using it, so it is yours to use without problem.

Just for kicks if you did enter a reserved word it would look like:

> finally
x SyntaxError: Unexpected token finally

Or if it was a native but already taken word it might look like:

> Node
function Node() { [native code] }

(Node is already defined, and its a native function)