Why? Because typically, you're doing that to use it somewhere else in the program.

为什么要这么做呢？因为你经常会在程序中,用到这一点。

麻省理工公开课 - 计算机科学及编程导论课程节选

You might ask, well why do they do splits?

你可能会问,他们为什么要这么做呢

耶鲁公开课 - 金融市场课程节选

Do you understand why we had to do this?

你知道为什么要这么做吗

耶鲁公开课 - 金融市场课程节选