Download Aptitude Crack
img not found img not found

Declarations and Access Control - Programming

Q1:

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; } }

A 1 only

B 2 only

C 3 and 5

D 1 and 4

ANS:A - 1 only

(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.