So the end result, because someone wrote this function years ago is that printf takes this thing, takes this thing, David plops David inside the middle of that formatted string and then renders the whole result.

基于这是某人多年以前写的程序,最终的结果是打印出这个，这个，在格式化字符串中间的,然后返回结果。

哈佛公开课 - 计算机科学课程节选