Java OCA OCP Practice Question 1036

Question

What is the output of the following code? (Choose all that apply) 

1: interface Area { 
2:   public default int getArea(int input) { return 2; } 
3: } //from w  w  w  .  j  ava2 s  . c o  m
4: public class Square implements Area { 
5:   public String getArea() { return "4"; } 
6:   public String getArea(int input) { return "6"; } 
7:   public static void main(String[] args) { 
8:     System.out.println(new Square().getArea(-1)); 
9:   } 
10: }
  • A. 2
  • B. 4
  • C. 6
  • D. The code will not compile because of line 5.
  • E. The code will not compile because of line 6.
  • F. The code will not compile because of line 8. 


E.

Note

The code doesn't compile because line 6 contains an incompatible override of the getArea(int input) method defined in the Area interface.

In particular, int and String are not covariant returns types, since int is not a subclass of String.

Note that line 5 compiles without issue; getArea() is an overloaded method that is not related to the parent interface method that takes an int value.




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