We look at what emails you reply to if you reply in theory that suggests this user must care about whoever sent this email or the topic they are in.

我们看看哪些邮件要回复,如果你回复了,理论上来说这表明了用户一定很关心,发件人以及邮件的主题。

哈佛公开课 - 计算机科学课程节选

But when you start writing programs, especially when we get to web-based stuff where you want -- to check the user's input -- is it valid, is it an email address, -- and all these different scenarios -- it's actually often useful to be able to just enumerate them or rattle them off using this switching construct instead.

但是当你看是写程序时，特别是当我们,使用基于网络的东西，你想要,检查用户的输入-,它是合法的吗？它是不是一个电子邮箱地址？,所有的这些场景-,实际上它常常是有用的，当你用枚举结构列举它们,或者用它来快速地来说出它们。

哈佛公开课 - 计算机科学课程节选