I think the parent is talking about how C for instance does not have optional parameters (for better or worse), if this was the case for JS everyone who has eve

I think the parent is talking about how C for instance does not have optional parameters (for better or worse), if this was the case for JS everyone who has ever used parseInt would be aware it takes a radix, but then again you also wouldn't be able to just plug it into map arbitrarily. Not saying one is better than the other, optional parameters can make for much less verbose code, I especially like parameter defaults introduced in ES6.