OCP JP Practice Exam 2 #29

[Jelo Nehuptra]

Why is it that the answer BCDF when B&D declares checked exception and the main method doesn't declare nor handle it?

import java.io.*;

class Physicist {
 void think() throws IOException {}
}

public class Feynman extends Physicist {

  public static void main(String[] args) {
     new Feynman().think();
   }

   // insert method here
}

A. void think() throws Exception{}
B. void think() throws FileNotFoundException{}
C. public void think(){}
D. protected void think() throws IOException{}
E. private void think() throws IOException{}
F. void think() {int x = 7/0;}

[Harsha Smith]

A is wrong because the overriding method must not throw new or broader checked exceptions.

E is wrong because you are reducing the visibility of the method.


B is correct because FileNotFoundException is the sub class of IO Exception(Narrow Exception)
C is correct because the overriding method may throw a fewer or no exceptions
D is correct because you aren't messing with the visibility of the method
F is correct for obvious reasons.

Additionally 'G' is also correct if exists. something like

G. void think() throws RunTimeException

[Jeffrey Tian]

Jelo Nehuptra wrote:Why is it that the answer BCDF when B&D declares checked exception and the main method doesn't declare nor handle it?

import java.io.*;

class Physicist {
 void think() throws IOException {}
}

public class Feynman extends Physicist {

  public static void main(String[] args) {
     new Feynman().think();
   }

   // insert method here
}

A. void think() throws Exception{}
B. void think() throws FileNotFoundException{}
C. public void think(){}
D. protected void think() throws IOException{}
E. private void think() throws IOException{}
F. void think() {int x = 7/0;}

I just finished this exam and didn't find the problem. The correct answers should be C & F.

[Dan Drillich]

Right, C & F are correct since Feynman().think() is now a brand new method.

Regards,
Dan

[Jelo Nehuptra]

Jeffrey Tian wrote:
I just finished this exam and didn't find the problem. The correct answers should be C & F.

What do you mean you didn't find the problem? It clearly says on pp. 210 that "B, C, D, and F are correct."

[Dan Drillich]

Jelo,

Not sure what the book says, but the following doesn't compile -

    import java.io.*;  
      
    class Physicist {  
     void think() throws IOException {}  
    }  
      
    public class Feynman extends Physicist {  
      
      public static void main(String[] args) {  
         new Feynman().think();  
       }  
      

      void think() throws FileNotFoundException{}  // option B
    }  

On

new Feynman().think();

We get -

Unhandled exception type FileNotFoundException

Regards,
Dan

[Jeffrey Tian]

Jelo Nehuptra wrote:

Jeffrey Tian wrote:
I just finished this exam and didn't find the problem. The correct answers should be C & F.

What do you mean you didn't find the problem? It clearly says on pp. 210 that "B, C, D, and F are correct."

Sorry for any misunderstanding. I should have said that I didn't find the problem you mentioned. The Answer given by the book is wrong.

[Harsha Smith]

main method "throws Exception" clause wasn't printed,I guess.