“第一个”定义符号的库将被使用。

The "first" library that defines the symbol is the one that gets used.

youdao

假如您不使用自定义符号，就删除此行。

If you don't use custom symbols, just delete this line.

youdao

它唯一的目的是在运行时检查给定的预定义符号是否被定义。

Its only purpose is to check at runtime whether or not the supplied preprocessor symbol is defined.

youdao

So this is the same definition we saw last time, just being a little bit more nerdy and putting in some notation.

这个定义和我们上次讲的是一致的,只不过使用了些符号使它变得有点枯燥

耶鲁公开课 - 博弈论课程节选

So compare the definition of words with what's written here in the nerdy notation on the board.

不妨去对比一下这个定义的,文字表述与黑板上的符号表述

耶鲁公开课 - 博弈论课程节选

But the take away for now is that if you don't clue -lcs50, -- you get some mention -- some error message -- about "undefined symbol," and that should be your clue that, "Oh it's undefined in that I haven't told the compiler that I want to link in these zeros and ones."

但现在如果你删除“-lcs50“,你们会得到一些提示--一些错误信息-,像“未定义的符号“，这可以为你提过线索，“这个没有被定义，我没有告诉编译器,把想把这个与“1“和“0“建立连接，“

哈佛公开课 - 计算机科学课程节选