Lambda function syntax in JavaScript without curly braces

Question

I just found out that the following (awesome) syntax is accepted by Firefox

f = function(x) x+1;
f(17) //gives 18

Does anyone know what the

Answer 1

This isn't part of a standard. The documentation is at https://developer.mozilla.org/en/New_in_JavaScript_1.8#Expression_closures_%28Merge_into_own_page.2fsection%29

There's discussion about adding some syntax along these lines or even shorter to the standard. See http://wiki.ecmascript.org/doku.php?id=strawman:shorter_function_syntax