What is this? This is a wonderful piece of abstraction. It is saying, you don't need to know squat about what's inside the body of this function. You don't have to worry about the parameter names, because they're going to be preserved, you don't need to worry about how I'm doing it, this tells you how you can use this, in order to use it correctly. Of course, I can then close it off, and off we go.

但是这能告诉你一些信息,这是什么？,这是一段完美的抽象,它的意思是你不需要知道,这个函数的内部构造，你不必担心参数是否重名，因为它们已经被预存了,你不需要担心我如何使用它,它告诉了你你该如何操作，从而正确的使用它，当然我也可以把它关掉。

麻省理工公开课 - 计算机科学及编程导论课程节选