I've never liked the aesthetics of a leading comma.... var foo = { bar: 100 , baz: 200 }; However the fact that (some) Javascript engines do

I've never liked the aesthetics of a leading comma.... var foo = { bar: 100 , baz: 200 }; However the fact that (some) Javascript engines don't like trailing commas... var foo = { bar: 100, baz: 200, // this borked the last time I tried it! }; causes me no end of trouble coming from regular Perl usage where they are allowed (and recommended best practise).