This is the java programming questions and answers section on "Interfaces" with explanation for various interview, competitive examination and entrance test. Solved examples with detailed answer description, explanation are given and it would be easy to understand.
1. Which of these keywords is used to define interfaces in Java?
- A. interface
- B. Interface
- C. intf
- D. Intf
Answer: Option A
Explanation:
interface
2. Which of these can be used to fully abstract a class from its implementation?
- A. Objects
- B. Packages
- C. Interfaces
- D. None of the Mentioned.
Answer: Option C
Explanation:
Interfaces
3. Which of these access specifiers can be used for an interface?
- A. Public
- B. Protected
- C. private
- D. All of the mentioned
Answer: Option A
Explanation:
Access specifier of interface is either public or no specifier. When no access specifier is used then default access specifier is used due to which interface is available only to other members of the package in which it is declared, when declared public it can be used by any code.
4. Which of these keywords is used by a class to use an interface defined previously?
- A. import
- B. Import
- C. implements
- D. Implements
Answer: Option C
Explanation:
interface is inherited by a class using implements.
5. Which of the following is correct way of implementing an interface salary by class manager?
- A. class manager extends salary {}
- B. class manager implements salary {}
- C. class manager imports salary {}
- D. None of the mentioned.
Answer: Option B
Explanation:
class manager implements salary {}
