单选题

The meaning of the Open-Close principle is that a software entity ( )

The container class can only access it through the interface of the contained object.

"Black box" reuse, good encapsulation, because the internal details of the contained objects are not visible to the outside world.

By obtaining references to other objects of the same type,Compositions (of objects) can be defined dynamically at runtime

Create extremely serious dependence.

delegation

inheritance

creation

none of the above

Template Method

Command

Memento

State

System maintenance and development

Object composition and class inheritance

System Architecture and System Development

System Reuse and System Expansion

The update of the observer role is passive.

The observed can notify the observer to update

The observer can change the state of the observed, and then the observed will notify all observers to proceed according to the state of the observed.

All the above statements are wrong.

Interface isolation

Liskov substitution

Dependency inversion

Demeter: An object should know as little as possible about other objects

Open-closed principle

Interface Segregation Principle

Liskov Substitution Principle

Dependency Inversion Principle

Inheritance

Encapsulation

Liskov substitution

Neither