https://en.wikipedia.org/wiki/Foobar
原文：
The terms foobar, foo, bar, baz and qux are sometimes used as placeholder names (also referred to as metasyntactic variables) in computer programming or computer-related documentation.[1] They have been used to name entities such as variables, functions, and commands whose purpose is unimportant and serve only to demonstrate a concept. The words themselves have no meaning in this usage. Foobar is sometimes used alone; foo, bar, and baz are sometimes used in that order, when multiple entities are needed.
译文：
术语foobar, foo, bar, baz 和qux经常在计算机编程或计算机相关的文档中被用作占位符的名字。当变量，函数，或命令本身不太重要的时候，foobar, foo, bar, baz 和qux就被用来充当这些实体的名字，这样做的目的仅仅是阐述一个概念，说明一个想法。这些术语本身相对于使用的场景来说没有任何意义。Foobar经常被单独使用；而当需要多个实体举例的时候，foo，bar，和baz则经常被按顺序使用。
本来源自博客地址：http://www.cnblogs.com/awpatp/archive/2011/02/27/1966380.html