Loose Coupling

“When two objects are loosely coupled, they can interact, but have very little knowledge of each other.”

Why?

• The only thing the subject knows about an observer is that it implements a certain interface (the Observer interface).
• We can add new observers at any time.
• We never need to modify the subject to add new types of observers.
• We can reuse subjects or observers independently of each other.
• Changes to either the subject or an observer will not affect the other.

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Resources