java--Abstract class

Abstract classes and abstract methods

• Abstract class:

Classes that are decorated with the abstract keyword are called abstract classes. An abstract class is a special class.

Definition syntax:

[Access modifier] Absrtact class class Name {[Class member]}

Description

The Absrtact keyword that is used to decorate the class. The class being decorated is called an abstract class.

Abstract and non-abstract methods can be included in an abstract class.

Application:

The implementation of the class as a template requires that the implementation in the child class be constrained.

• Abstract methods

Overview:

The method of modification by the abstract broad-Jian character is called an abstraction method. An abstract method has no method body and can only be defined in an abstract class.

Grammar:

[Access modifier] Abstract return value type method name ([parameter list]);

Characteristics:

Abstract methods can only be defined in abstract classes

An abstract method has no method body and must be implemented in a non-abstract subclass

Role:

Constrain subclasses to improve extensibility.

java--Abstract class