Behavioral Design Patterns in C++ - Change Manager - I

The video tutorial explains the observer pattern, initially with a single subject, and then addresses the challenges that arise when multiple subjects are involved. To manage dependencies between subjects and observers, the change manager is introduced as a mediator, following the mediator design pattern. The change manager handles notifications and maintains mappings, reducing the need for direct dependencies. The tutorial concludes with a preparation for implementing this pattern in code.

What is the primary challenge when observers depend on multiple subjects?

• Observers need to track multiple subjects, increasing dependencies.

• Subjects cannot send notifications to observers.

• Observers can only register for one type of notification.

• Subjects and observers must be in the same class.

What role does the change manager play in the observer pattern?

• It replaces the observers entirely.

• It acts as a mediator between subjects and observers.

• It sends notifications directly to the subjects.

• It stores data from all subjects.

How does the change manager help in reducing dependencies?

• By allowing subjects to directly notify observers.

• By maintaining a list of observers for each subject.

• By eliminating the need for notifications.

• By managing the interaction between subjects and observers.

What is the responsibility of the change manager when a subject changes its state?

• To notify the observers about the change.

• To ignore the change.

• To change the state of all observers.

• To update the subject's state.

What is the next step after understanding the change manager's role?

• Stop using the change manager.

• Remove all observers.

• Create more subjects.

• Implement the concept in code.