Final answer:
The Observer pattern is a behavioral design pattern that establishes a one-to-many relationship between a subject and its observers. It allows the subject to notify its observers automatically when its state changes.
Step-by-step explanation:
The Observer pattern is a behavioral design pattern that allows an object, called the subject, to maintain a list of its dependents, called observers, and notify them automatically of any state changes. This pattern is commonly used in software development to establish a one-to-many relationship between the subject and its observers. When the subject's state changes, all its observers are updated accordingly.
For example, imagine a weather station as the subject and various displays (e.g., temperature display, humidity display) as the observers. Whenever the weather station receives new data, it notifies all the displays, and they update their information accordingly.
Using the example provided, if you are observing your friend riding a skateboard and tossing a ball, your friend will observe the ball toss from their perspective. They will see the motion of the ball and its trajectory. On the other hand, your observation will include the friend's motion, the direction they are facing, and the path of the ball in relation to the skateboard's movement.