5.8 Information hiding within a class 信息隐藏在类中

The examples in this chapter focused on information hiding as it relates to the externally visible APIs for classes, but information hiding can also be applied at other levels in the system, such as within a class. Try to design the private methods within a class so that each method encapsulates some information or capability and hides it from the rest of the class. In addition, try to minimize the number of places where each instance variable is used. Some variables may need to be accessed widely across the class, but others may be needed in only a few places; if you can reduce the number of places where a variable is used, you will eliminate dependencies within the class and reduce its complexity.

本章中的示例着重于信息隐藏，因为它与类的外部可见 API 有关，但是信息隐藏也可以应用于系统中的其他级别，例如类内。尝试在一个类中设计私有方法，以便每个方法都封装一些信息或功能，并将其隐藏在类的其余部分中。此外，请尽量减少使用每个实例变量的位置数量。有些变量可能需要在整个类中广泛使用，但是其他变量可能只需要在少数地方使用；如果可以减少使用变量的位置的数量，则将消除类内的依赖关系并降低其复杂性。