Well, the user, I don't know in advance what the user is going to type in, right?

我不能预先知道,用户将要输入神秘，对不？

哈佛公开课 - 计算机科学课程节选

I can't rely on Professor Guttag if I give this- if this code to him, I can't rely on him to type in a float. Actually I can, because he's a smart guy, but in general, I can't rely on the user-- I wouldn't do it right to see if you did.

当Guttag使用这段代码的时候-,我不能相信他一定会输入一个浮点数,实际上我能因为他很聪明，但是总体上来讲，别相信用户一定会按照规则来-,我会故意做错来试试你的程序的。

麻省理工公开课 - 计算机科学及编程导论课程节选

Why is this "3" running right into my Malan user name there?

为什么这个“3“显示在我的Malan用户名前面？

哈佛公开课 - 计算机科学课程节选