1. Functional Decomposition: Structured programmers always use functional decomposition program design. Functional decomposition is a problem will gradually break down into smaller functional way, each function are broken down into manageable so far.
2. The demand for change reasons:
- Users think about their needs will change as new possibilities for software developers and discuss and see occur.
- Developers field of view of the user's problem, will enable the development of the field of automated software process, because it is more familiar and change.
- Future not on. The future development of unpredictability, people can only make general predictions of a field. Now the view advanced in the future may become a backward point of view. (Mvc, mvp)
3. For use responsibility needs to think, not to think about functionality.
Self-understanding: Students in class, reading, homework is my function. But it is not my responsibility. My responsibility is to make the future what kind of person. But this is my responsibility, I do not have to implement it. Because I can not do his own future a precise definition.
4. Coupling: The closeness of contact between the two routines.
Cohesion: the close link between the degree of routine operations.
Software development due to the pursuit of low coupling, high internal poly.
Low coupling: Due to the link between different routines loose. So that each thread size, carry out their duties.
High cohesion: on the basis of low coupling, be responsible for functional components function, due to close contact.
Question: If demand occurred after this change internal functions. Splitting component functions not that difficult. Or create a new function to complete the requirements.
The object of the interface object: hide the technical details of the external internal implementation.
Use of encapsulation, polymorphism, interfaces to hide the internal implementation process implemented.
Example 6: specific object class.
7. The definition of the class behavior of objects, comprising three parts:
- Object contains data elements
- The method objects can operate
- Access these data elements and methods
8. abstract class: defines a set of class a method similar to the concept of public properties. An abstract class can not be instantiated.
9. accessibility four kinds of class:
- public: public, ie, all objects accessible.
- protect: protection, you can access the same package and subclasses.
- default: By default, the same package.
- private: private, accessible to the current class.
10. Package: hidden in any form. Object encapsulates its data, the abstract class encapsulates its derived concrete class.
11. Polymorphic: capability implemented method related objects according to their specific type.
12. The three observation target Perspective:
- concept
- specification
- achieve