It's not true, by the way, of all programming languages. In fact, Professor Guttag already talked about that, in some languages lists take a time linear with the length to get to it.
顺便说一句这在大部分，编程语言中做不到，实际上Guttag教授已经说过这一点了，在一些语言中取得数组,要花费时间是线性长度的。
麻省理工公开课 - 计算机科学及编程导论课程节选
