What are common OO code smells, and how can refactoring address them?

What are common OO code smells, and how can refactoring address them?

• A. Code smells are purely aesthetic and do not impact maintenance.
• B. Refactoring eliminates all bugs.
• C. Common smells include God classes, long methods, feature envy, and tight coupling; refactor by extracting responsibilities and simplifying interfaces.
• D. Refactoring is only done after deployment.

Answer: (C)

Recognizing OO code smells helps you spot parts of the design that are hard to maintain or extend. Common smells include God classes that take on too many responsibilities, long methods that are difficult to read and reason about, feature envy where one class frequently manipulates another class’s data or behavior, and tight coupling where many parts of the system depend closely on each other. Refactoring targets these issues by reshaping the code without changing its external behavior: extracting responsibilities into separate classes or moving methods to the class that owns the data, breaking up large methods into smaller and more cohesive units, moving data and behavior to the appropriate owner to reduce feature envy, and simplifying interfaces to ease interaction and reduce dependencies. The aim is to improve readability, testability, and maintainability, not to claim that all bugs are gone. It’s also not accurate to say smells are merely aesthetic, nor that refactoring fixes every bug, nor that refactoring is only done after deployment; it’s a practice used throughout development to keep designs clean and evolvable.

Recognizing OO code smells helps you spot parts of the design that are hard to maintain or extend. Common smells include God classes that take on too many responsibilities, long methods that are difficult to read and reason about, feature envy where one class frequently manipulates another class’s data or behavior, and tight coupling where many parts of the system depend closely on each other. Refactoring targets these issues by reshaping the code without changing its external behavior: extracting responsibilities into separate classes or moving methods to the class that owns the data, breaking up large methods into smaller and more cohesive units, moving data and behavior to the appropriate owner to reduce feature envy, and simplifying interfaces to ease interaction and reduce dependencies. The aim is to improve readability, testability, and maintainability, not to claim that all bugs are gone. It’s also not accurate to say smells are merely aesthetic, nor that refactoring fixes every bug, nor that refactoring is only done after deployment; it’s a practice used throughout development to keep designs clean and evolvable.