That goes back to that idea of sort of discipline coding. It's easy to have assumptions about what you think are going to come into the program when you writ it. If you really know what they are use them as search, but if you think there's going to be some flexibility, you want to prevent the user getting trapped in a bad spot, and exceptions as a consequence are a good thing to use.

这又回到了规范编码的想法上来了,在你写代码的时候考虑,什么会进入你的代码的思考是简单的,如果你真的知道,他们是用他们来做搜索的,而你希望有一定的灵活性，你想要阻止用户,陷入一个艰难的境地,那么异常是非常实用的。

麻省理工公开课 - 计算机科学及编程导论课程节选