Which two statements correctly describe capabilities of interfaces and abstract classes? (Choose two.)

Question

Options

• AInterfaces cannot have protected methods but abstract classes can.
• BBoth interfaces and abstract classes can have final methods.
• CInterfaces cannot have static methods but abstract classes can.
• DInterfaces can have methods with bodies but abstract classes cannot.
• EInterfaces cannot have methods with bodies but abstract classes can.

• A
  78% (40)
• B
  12% (6)
• D
  6% (3)
• E
  4% (2)

Explanation

Option A is correct because interface methods must be public (or in Java 9+, private) - protected is not a valid access modifier for interface members. Abstract classes, by contrast, freely support protected methods, making A an accurate distinction.

Option C is correct in the context of this exam (targeting pre-Java 8 behavior), where interfaces were restricted to abstract method declarations and static methods were only permitted in abstract classes. Be aware that Java 8+ did add static method support to interfaces, so this answer assumes a traditional or pre-Java-8 model.

B is wrong because interfaces cannot declare final methods - final means "cannot be overridden," which conflicts with the requirement that interface methods be implemented by subclasses. Abstract classes can have final concrete methods.

D is wrong because it inverts the truth: abstract classes have always supported concrete methods with bodies, while interfaces (pre-Java 8) could not.

E is wrong because in Java 8+ interfaces can have methods with bodies via default and static keywords, making the absolute statement false.

Memory tip: Think of an abstract class as a partial blueprint (can do almost everything a regular class can) and an interface as a strict contract (historically only public, abstract, no statics, no implementation) - restrictions relax with each Java version.

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