说到类和对象，我们不能不提及这样几个概念：类，对象，实例。就我个人觉得可 以这样来理解：对象指的是泛称，自然界的任何实体都可以看成一个对象；而类则是 以这些对象某些特征而分成的一系列的种类；实例则是特指属于某一个类的一个对象-said classes and objects, we can not fail to mention the following concepts : type, object, examples. I personally think that this can be understood : the targets refer to the Pan said that the nature of any entity can be viewed as an object; Which category is the target certain features into a series of categories; Examples are an indicator of belonging to a certain category of an object