Javascript performance of indexing

Question

以下行是否被认为不是最佳行，特别是考虑到它已在许多地方或循环内使用：

var age = myObject[index]["Person"]["Identity"]["Bio"]["Age"]

Answer 1

Even if hash lookup in Javascript is O(1) (I don't know for sure), you'd still have the overhead of the lookup operations. So, yes, this is suboptimal for a big loop.