Phase 1 Language Basics + Advanced _1-3-Java language senior _02- inheritance and polymorphism _ Section 7 of the inner class _18_ _ red envelopes Case Analysis

There is only one divide the interface method, the division mean




it's a graphical interface, do not do research here.


It is an abstract class


new red MyRed class implements an interface

Alt + Enter. By default the first option,


which is only a constructor, there is no no-argument constructor

so subclasses must call the parent class has constructor parameters










click so and so



three things that need to do their own