So just to hammer home this point, for now, a function really is like a black box.

现在再三强调，让你们彻底了解这一点，一个函数就像是一个黑盒子。

哈佛公开课 - 计算机科学课程节选

There's a famous saying, "If you're good with a hammer, everything looks like a nail."

正像一句名言说的那样，如果你很会用锤子，那么一切看上去都是钉子“

耶鲁公开课 - 金融市场课程节选