This just means hexadecimal notation, which we'll come back to before long so really it just means it's returning the 0 address zero.

这表示的是16进制,我们等下还会讨论，表示的是返回,地址。

哈佛公开课 - 计算机科学课程节选

Now the address zero I said I think on Monday is special.

周一我说过的地址0是专用的。

哈佛公开课 - 计算机科学课程节选