And when you declare a variable, whether as an argument or as literally a local variable, they only live inside of that function.

当你声明一个变量，不论是一个参数,还是一个局部变量，它们只存在函数的内部。

哈佛公开课 - 计算机科学课程节选

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

So it's got an internal procedure,internal function, local to the unit test, that runs the simulation.

它有内部过程，内部函数，它对unit，test来说是有本地环境，来支持股票仿真程序的运行。

麻省理工公开课 - 计算机科学及编程导论课程节选