"Java初级chap05：面向对象编程特性与访问控制"

The PowerPoint document "java初级chap05(ppt文档).ppt" covers the characteristics of Object-Oriented Programming (OOP), specifically focusing on Encapsulation, Inheritance, and Polymorphism. Encapsulation, discussed in Chapter 5, is the concept of hiding the implementation details of a class and providing access to the data through methods. This helps in maintaining the integrity of the data and prevents outside interference. Inheritance, explained in Chapter 6, allows a class to inherit properties and behavior from another class. This promotes code reusability and helps in creating a hierarchy of classes. Polymorphism, which is the focus of Chapter 7, allows objects to be treated as instances of their parent class or their own class. This enables flexibility in the design and implementation of classes. The presentation also delves into access control in Java, including the use of packages as a library unit for organizing classes. It emphasizes the creation of unique package names to avoid collisions, and the use of imports to change behavior. The document also discusses Java access specifiers, such as "friendly," public, private, and protected, and their roles in controlling access to classes and members within a package. Additionally, the presentation covers interface and implementation, class access, and provides exercises to reinforce the concepts discussed. Overall, the PowerPoint presentation "java初级chap05(ppt文档).ppt" provides a comprehensive overview of OOP principles, access control in Java, and the importance of packages in organizing and managing classes. It serves as a valuable resource for individuals looking to deepen their understanding of Java programming at an introductory level.