SingleInheritance.md

Inheritance (C++)

Definition

Inheritance allows one class (derived) to acquire properties/behaviors of another class (base).

Minimal Example

• Animal = base class with eat()
• Dog = derived class that reuses eat() and adds bark()

Interview Quick Line

"Inheritance is an is-a relationship. A Dog is an Animal, so it can reuse Animal behavior and add specific behavior."

Common Interview Points

• Use inheritance for real is-a relationships.
• Prefer public inheritance for behavioral substitutability.
• Don’t overuse inheritance when composition can do better.

5-Year Interview Perspective

• Ask first: "Do I need subtype polymorphism or just code reuse?"
• Keep base classes cohesive and behavior-focused, not data-heavy.
• Avoid fragile base class design by minimizing virtual surface area.