Using typeof to typeof doesn't work in Javascript

Question

So I get how typeof can be an operator or a function. But when I do

console.log(typeof(typeof));

I got this message Uncaught SyntaxError: Unexpected token ')'

So what am i doing wrong here? What can i do to get the data type of typeof?

typeof(+) (or typeof +, since it is indeed an operator and therefore doesn't need parentheses) fails with the same error, which hopefully isn't a surprise. Despite it being all alphanumeric characters, typeof is an operator just like + and friends, so it behaves the same way. — Robin Zigmond
– Robin Zigmond, Commented Sep 15, 2020 at 21:46
I think this is a fine question. It bothers me that someone would downvote this and vote to close. — Slbox
– Slbox, Commented Sep 15, 2020 at 21:51
This is a common mistake made by beginners. Just because one can wrap parenthesis around an operand it does not turn the preceding operator into a function. — Peter Seliger
– Peter Seliger, Commented Sep 15, 2020 at 22:06
Removing all the content is considered vandalism. Please don't do this. Questions and answers at StackOverflow are not a free service for you exclusively but shall also help other visitors with similar problems. — Gerhardh
– Gerhardh, Commented Nov 26, 2021 at 7:35

HoldOffHunger · Accepted Answer · 2020-09-15 22:02:22Z

2

typeof is an operator. (Source: MDN Web Docs: typeof.)

To sum up the documentation on operators, I'll say this: Every operator must work on an operand (or non-operator). A unary operator requires only one operand (i++, !j), a binary operator requires two operands (1+2, 'a' + 'b'), and there's even a special ternary operator. (Source: MDN Web Docs: Expressions and operators.) Or, if you like the original text...

A binary operator requires two operands, one before the operator and one after the operator...

A unary operator requires a single operand...

So, it's not possible to do...

+ +
+ ==
typeof +

Etc.. Naturally, then, typeof typeof will naturally not work, as it violates the rule about unary operators requiring operands.

answered Sep 15, 2020 at 22:02

HoldOffHunger

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