UML Study Notes (2): review some basic object-oriented concepts

 

 

Object-oriented thinking is a library that relies on several basic principles.

The object is a class instance.

Class is an object set with the same attributes and operations.

Inheritance is an important aspect of object orientation. The object inherits the attributes and operations of the class. Classes can also inherit the attributes and operations of other classes.

Polymorphism is another important aspect. It means that operations with the same name can be performed in different classes in different ways.

An object hides the execution process of its operations on other objects and the external world. Each object must provide an interface for other objects to perform operations on this object.

Objects work collaboratively through mutual message transmission. A message is a request to perform an operation.

Objects are usually associated with other objects. Association can take multiple forms. Objects of a class may be associated with objects of multiple other classes at the same time.

Clustering is an association. Clustering objects are composed of some objects. Composition is a special aggregation. In a composite object, some objects can only exist as part of the composite object and the composite object.

 

Source: http://www.cnblogs.com/Bear-Study-Hard/archive/2006/06/02/415828.html