It's a bad habit to get into, because when you come back to it, it may haunt you later on down the road. So really get into that notion of trying to be defensive as you program.

来运行程序的时候,错误就会出现缠住你了,因此现在我们真的要培养,在程序中有防卫性设计的概念。

麻省理工公开课 - 计算机科学及编程导论课程节选

Now, unlike high school math or in algebra Z where you call things X and Y and Z, in programming, in computer science, you're actually dealing with humans where it's useful to have a variable name that's more descriptive than X and Y and Z.

不像高中数学或者代数中,称为X和Y和，在程序设计和计算机科学里，你实际上是在和人打交道,在这里有个描述性比xyz更强的,变量名称是很重要的。

哈佛公开课 - 计算机科学课程节选