Why does 3.toString() throw a syntax exception and 3..toString() works fine?

Question

why in javascript 3.toString() throws exception and 3..toString() works fine? I saw it in a funny presentation about javascript but I cannot find the info WHY. Thank you in advance.

Answer 1

Because a decimal point is a valid portion of a number, so the first dot is considered numeric, the second is for chaining.

If you'd prefer to avoid the double-period you could instead do:

(3).toString();

Or:

'' + 3;

Or:

String(3);