I disagree with this post. The semantics are clear and simple: if you assign,maps to a function or return from a function any array you can treat it as a copy o

I disagree with this post. The semantics are clear and simple: if you assign,maps to a function or return from a function any array you can treat it as a copy of the array. As a performance optimisation the copy usually won't happen as it won't be needed. If you are dealing with large enough arrays that it matters wrap the array in an object that can be passed by reference. I strongly opposed to original semantics and blogged about it. I am happy with the replacement.