Java OCA OCP Practice Question 386

Question

What is the output of the following application? 

1: public class MyClass { 
2:     public void calculateResult(Integer myFieldA, Integer myFieldB) { 
3:       boolean process = myFieldA == null || myFieldA.intValue() < 10; 
4:       boolean value = myFieldA && myFieldB; 
5:       System.out.print(process || value); 
6:    } /*from   ww w  .  j  a  v  a 2 s. co m*/
7:    public static void main(String[] unused) { 
8:       new MyClass().calculateResult(null,203); 
9:    } 
10: }
  • A. true
  • B. false
  • C. The code does not compile.
  • D. The code compiles but throws a NullPointerException on line 3 at runtime. 


C.

Note

On line 4, myFieldA and myFieldB are numbers, but the && operation can only be applied to boolean expressions.

The code does not compile because of line 4, making C the correct answer.

All of the other lines are correct. Note that if line 4 is fixed, line 3 does not produce a NullPointerException at runtime.

The conditional || and the preceding null check allows the code to only call intValue() if myFieldA is not null.




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