Which of the following statements best captures the behaviour of interfaces…
2025
Which of the following statements best captures the behaviour of interfaces when one interface extends another in object-oriented design?
- A.
An interface can only extend a single class, but not another interface.
- B.
An interface cannot be extended or implemented further once defined.
- C.
When one interface extends another, it inherits all constants and method declarations from the parent interface.
- D.
Interfaces can implement other interfaces to share functionality.
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Correct answer: C
When a sub-interface extends a parent interface, it establishes an inheritance relationship. Because interfaces are purely abstract blueprints, the sub-interface naturally inherits all the method declarations (signatures) and constants defined in the parent interface. This forms a larger, combined contract. Consequently, any concrete class that eventually chooses to implement that sub-interface must provide working code implementations for every single method throughout the entire inheritance chain.