我们不能实例化一个抽象类，即使它们的字段和方法都是具体的。

We can't instantiate instances of abstract classes, even when all their field and method members are concrete.

youdao

客户类中的第二个 find 方法是 findAllOrder()，它使用了一个包含搜索到的对象类型和该实例的客户 ID 的密钥。

The second find method in the customer class, findAllOrder(), uses a key with the searched object type and the customer ID of this instance.

youdao

这个方法接受要显示的文本和一个默认的TextPresentation实例。

This method receives the text to be presented and a default TextPresentation instance.

youdao

These are both altogether called attributes of the instance.

因此在一个实例里面,与之相关联的，是方法和域。

麻省理工公开课 - 计算机科学及编程导论课程节选