1.
Consider the following interface and class:
Public interface A {
public void m1( );
public void m2( );
}
Public class C implements A {
// code for class C
}
What must be true about the code for class C in order for that code to compile successfully?
A.
class C should have at least one call each for methods m1 and m2
class C should contain an abstract method m1 and abstract method m2
class C does not have to do anything as it already "implements" class A and has inherited both
m1 and m2
class C should contain the definitions of methods m1 and m2 as concrete methods (fully written
methods included in class C that contains code in the method bodies)
A. class C should have at least one call each for methods m1 and m2
B. class C should contain an abstract method m1 and abstract method m2
C.
class C does not have to do anything as it already "implements" class A and has inherited
both m1 and m2
D.
class C should contain the definitions of methods m1 and m2 as concrete methods (fully
written methods included in class C that contains code in the method bodies)
Solution

2.
Answer is D. When you implements a class then you have to fully write the methods which are
present in its interface. Class implementing any interface must implement all the methods,
otherwise the class should be declared as “abstract―.