Now I have the ability to say, I've got a new class, I can create instances of a line segment, and it's elements are themselves instances of points. OK?

这就是我们要讲模块化的地方了，现在我可以说，我创建了一个新类，我可以创建线段的实例了,这些实例的元素？

麻省理工公开课 - 计算机科学及编程导论课程节选