Thinking in Java Reading Note (8. Polymorphism)

1. Polymorphism Overview

Polymorphism does what and how by separating , separating the interface from the implementation from another angle . Polymorphism not only improves the organization and readability of code, it also creates extensible programs---programs that can "grow" whenever a project is initially created or when new functionality is needed.

　　Encapsulation Creates a new data type by merging features and behaviors . "Implementation concealment " separates the interface and implementation by "privatizing" the details.

The role of polymorphism is to eliminate the coupling relationship between types . As we know in the previous chapter, inheritance allows an object to be treated as its own type or its base type. This ability is extremely important because it allows multiple types (derived from the same base class) to be treated as the same type, and the same code can run without distinction on these different types . a polymorphic method call allows a type to exhibit differences from other similar types as long as they are all from the same base class . This distinction is based on the different behavior of the method, although these methods can be called by the same base class .

2. Transfer

Method call Binding

　　

　　

Thinking in Java Reading Note (8. Polymorphism)