interface DoMath
{
double getArea(int rad);
}
interface MathPlus
{
double getVol(int b, int h);
}
/* Missing Statements ? */
which two code fragments inserted at end of the program, will allow to compile?
1.class AllMath extends DoMath { double getArea(int r); }
2.interface AllMath implements MathPlus { double getVol(int x, int y); }
3.interface AllMath extends DoMath { float getAvg(int h, int l); }
4.class AllMath implements MathPlus { double getArea(int rad); }
5.abstract class AllMath implements DoMath, MathPlus { public double getArea(int rad) { return rad * rad * 3.14; } }
Answer: C
(3) are (5) are correct because interfaces and abstract classes do not need to fully implement the interfaces they extend or implement (respectively).
(1) is incorrect because a class cannot extend an interface. (2) is incorrect because an interface cannot implement anything. (4) is incorrect because the method being implemented is from the wrong interface.