1.toString() SyntaxError in Javascript

Question

Why the first line below gives error although the second and third lines work fine?

1.toString(); // SyntaxError
(1).toString(); // OK
1[\'toString\'](); //          


        

Answer 1

The . presents ambiguity. Is it a decimal, or a property accessor?

The interpreter sees it as a decimal, so you can use .. to allow both the decimal, then the property syntax.

1..toString();

Or use one of the other ways you show to resolve the ambiguity.