interface Base{
boolean m1 ();
byte m2(short s);
}
which two code fragments will compile?
1. interface Base2 implements Base {}
2. abstract class Class2 extends Base
{ public boolean m1(){ return true; }}
3. abstract class Class2 implements Base {}
4. abstract class Class2 implements Base
{ public boolean m1(){ return (7 > 4); }}
5. abstract class Class2 implements Base
{ protected boolean m1(){ return (5 > 7) }}
interface Base{
boolean m1 ();
byte m2(short s);
}
1. interface Base2 implements Base {}
2. abstract class Class2 extends Base
{ public boolean m1(){ return true; }}
3. abstract class Class2 implements Base {}
4. abstract class Class2 implements Base
{ public boolean m1(){ return (7 > 4); }}
5. abstract class Class2 implements Base
{ protected boolean m1(){ return (5 > 7) }}
A. 1 and 2
B. 2 and 3
C. 3 and 4
D. 1 and 3
E. 4 and 5
Answer: Option C
Solution(By Examveda Team)
(3) is correct because an abstract class doesn't have to implement any or all of its interface's methods. (4) is correct because this method is correctly implemented ((7 > 4) is a boolean).
(1) is incorrect because interfaces doesn't implement anything. (2) is incorrect because classes don't extend interfaces. (5) is incorrect because interface methods are implicitly public, so the methods being implemented must be public.
A. A contract specifying a set of methods that a class must implement
B. A class that cannot be instantiated
C. A class that contains only static methods
D. A subclass of the Object class
In Java, can a class implement multiple interfaces?
A. Interfaces cannot be implemented by classes
B. Only abstract classes can implement interfaces
C. No, a class can only implement one interface
D. Yes, a class can implement multiple interfaces
What is the purpose of an abstract class in Java?
A. To declare abstract methods
B. To provide a base class with common methods and fields
C. To make a class final
D. To declare abstract methods
Join The Discussion