You've got a magnetic field, maybe even magnetic susceptibility, the electric field. We're not going to worry about these magnetic fields or electric fields in this class So, pretty much we're going to focus on this set of variables here.

你也会引入磁场，或许甚至磁化率，以及电场，我们这堂课不需要关心,这些磁场或,电场之类的东西,基本上我们只关注,这里的一组变量。

麻省理工公开课 - 热力学与动力学课程节选

Notice that that typically also defines for me what the internal variables are, what the internal characteristics of the class are going to be.

就放进去是比较好的,我写下了init声明意思就是，当你创建一个实例的时候,这就是你要进行的操作。

麻省理工公开课 - 计算机科学及编程导论课程节选