But there are no official "rules" for a Thanksgiving meal.

VOA: special.2009.11.23

This chart, very boring and uninteresting but useful to say there are very well defined rules as to when you're writing code, what operators, like what syntax should get evaluated first.

这个图表，看起来很烦，很无趣，但是它很有用,有非常明确的规定,譬如，当你写代码时，就会涉及操作符的优先级。

哈佛公开课 - 计算机科学课程节选