What does "Open/Closed Principle" mean in programming?
Open/Closed Principle is one of the most common terms in software development. This guide explains what it means, how it is used in practice, and why it matters, with real examples from the developer world.
Definition
The O in SOLID. Software entities should be open for extension but closed for modification. Add new behavior by writing new code (subclasses, strategies, plugins) rather than changing existing code. This reduces the risk of introducing bugs when adding features.
Example
"Instead of adding an if-else for each new payment method, we added a new PaymentStrategy class. The processor is open for extension, closed for modification."
Related terms
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