So it does that for us so that you can get away with just knowing the address of the first byte and it will make sure that you know when to stop by including the special value so, in fact, get the string if you type in a three-letter word, we allocate four bytes no matter what because we need an additional byte 0 for this special sentinel value back slash zero at the very end.

它为我们做了这些事情，这样我们就可以,通过第一个字节的地址,它还可以通过包含一个特殊的值,来保证在哪里停止，如果你输入了一个三个字母的单词,就可以获得那个字符串，不管怎样，我们分配四个字节,因为我们在末端需要一个额外的字节,来保存这个特殊的标志值--反斜杠。

哈佛公开课 - 计算机科学课程节选

X That's just the special symbol in C that says don't pass X, that is don't pass a copy of X. Rather figure out where x is in memory, where he is in that frame and provide swap the numeric address in RAM of that value so that swap can go do anything it wants at that address.

这在C中是一个特殊的符号，指明不传送，也不是传递X的拷贝，而是指出x在内存中哪个地方,它在那个框架中的哪个地方,提供给swap它的地址值,这样swap就可以使用那个地址中的数据。

哈佛公开课 - 计算机科学课程节选