6. What type of variable can be defined in an interface?

1. 1. public final

   
   
   

   2. public static

   
   
   

   3. static final

   
   
   

   4. private final

   
   
   

   5. None of these

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   variable defined in an interface is implicitly final and static. They are usually written in capital letters.

---

7. All methods must be implemented of an interface.

1. 1. False

   
   
   

   2. True

   
   
   

   3. NA

   
   
   

   4. NA

   
   
   

   5. NA

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   Concrete classes must implement all methods in an interface. Through interface multiple inheritance is possible.

---

---

8. Which of the following is the correct way of implementing an interface N by class M?

1. 1. class M imports N{}

   
   
   

   2. class M extends N{}

   
   
   

   3. class M implements N{}

   
   
   

   4. All of above

   
   
   

   5. None of these

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   Concrete class implements an interface. They can be instantiated.

---

9. Which of these can be used to fully abstract a class from its implementation?

1. 1. Interfaces

   
   
   

   2. Objects

   
   
   

   3. Packages

   
   
   

   4. All of above

   
   
   

   5. None of these

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   Interfaces

---

---

10. Which of these access specifiers can be used for an interface?

1. 1. private

   
   
   

   2. Public

   
   
   

   3. Protected

   
   
   

   4. All of above

   
   
   

   5. None of these

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   Access specifier of an 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.

---