201671010135 2016-2017-2 "Java programming" to the problem around the first

Dazzling has been learning Java for four weeks, feeling that it has not been a weekend since the week. Every person in the experiment can be completed on time, can master the knowledge of the content, even if a half, feel that such a life is boring and boring. Self-learning ability is poor, if you are interested in things to learn good, also is not to say that Java is not interested in, just feel that their interests are anxious polished. The knowledge you have learned is also ambiguous.

1. Why must there be an abstract class concept? Why can't we just write this parent class into a specific class, and subclass it to inherit it? Why get an abstract class out, but also to make some no method of the body of abstract methods, and like the interface and like the class, people are unpredictable.

2. Why can subclasses inherit the methods and fields of the parent class, but not the constructors of the parent class?

3. The paragraph in the middle of the p149 page does not understand. Isn't the manager class already inheriting the methods and classes in Emploeey? Why can't I access his private domain????? Is all common methods available as interfaces?

Ah hey ah ah ah ah .....

201671010135 2016-2017-2 "Java programming" to the problem around the first