Java OCA OCP Practice Question 982

Question

Which of the following complete the constructor so that this code prints out 50?

Choose all that apply 

public class Main {  
  int numSpots; 
  public Main(int numSpots) { 
    // INSERT CODE HERE 
  }  
  public static void main(String[] args) { 
    System.out.println(new Main(50).numSpots); 
  } 
} 

A.  numSpots = numSpots; 
B.  numSpots = this.numSpots; 
C.  this.numSpots = numSpots; 
D.  numSpots = super.numSpots; 
E.  super.numSpots = numSpots; 
F.  None of the above. 



C.

Note

Within the constructor numSpots refers to the constructor parameter.

The instance variable is hidden because they have the same name.

this.numSpots tells Java to use the instance variable.

In the main() method, numSpots refers to the instance variable.

Option A sets the constructor parameter to itself, leaving the instance variable as 0.

Option B sets the constructor parameter to the value of the instance variable, making them both 0.

Option C is correct, setting the instance variable to the value of the constructor parameter. Options D and E do not compile.




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