I want the function, which is a little tool, a line of code I can include in my own programs and generally those tools live in sections two or three of the manual.

我想要一个函数，那是一个小工具，在我程序中可以包含的一行代码,通常这些工具在手册的第二节,或第三节。

哈佛公开课 - 计算机科学课程节选

The standard library, that first line of code, it's not strictly necessary but any time you use a function, a tool that someone else wrote that lives in that so called library, you do need that include line as we'll see.

标准库函数--第一行代码，严格来说，不是每次都要写的，但是一旦你调用某个别人写，的函数，而这个函数又恰巧位于标准库里面,你就要像我们看到的这样，把它include进去。

哈佛公开课 - 计算机科学课程节选