I understand your question now was more about function scoping versus block scoping from a language design perspective, and not about specific to JavaScript. It

I understand your question now was more about function scoping versus block scoping from a language design perspective, and not about specific to JavaScript. It wasn't clear from your comment you were heading in that direction. Having var enable you to make use of function scoping is useful to JavaScript developers who have, up until this point in history, have always had function scoping. As parent mentioned, using var allows you define the variables where you are. It makes the code more readable. As far as function scoping versus block scoping I don't have much of a say, as I am not sure there are any meaningful advantages, merely minor ones, but none that would impact productivity if you were experienced in one or the other. Maybe you could convince me otherwise?