Multiple choice

interface DoMath { double getArea(int rad); } interface MathPlus { double getVol(int b, int h); } /* Missing Statement(s) ? */ Which code fragment(s) 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; } }

  1. 1 only

  2. 2 only

  3. 3 and 5

  4. 1 and 4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

(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.

Keep practicing — related questions