Exception

[Shiva Mohan]

Skillfox discussion forum question

    
try {
tryThis() ;
return;
} catch (IOException x1) {//--------------line 1
System.out.println("exception 1") ;
return;
} catch (Exception x2) {
System.out.println("exception 2") ;//line 2
return;
} finally {
System.out.println("finally") ;
}

What will appear in the standard output if tryThis() throws a NumberFormatException?
a. Nothing
b. "exception 1", followed by "finally"
c. "exception 2", followed by "finally"
d. "exception 1"
e. "exception 2"

The answer they have given is c.But when i execute the program ,i got the error at line 1 telling
IOException is never thrwon in try block.Please clarify

[Chandra Bhatt]

You are correct ShivMohan!!!
Some mock exams confuse us; Very bad;


NumberFormatException(unchecked exception) IS-A IllegalArgumentException IS-A RuntimeException;

RuntimeException
      ^
      |
      |
      | 
IllegalArgumentException
      ^
      |
      |
      |
NumberFormatException

IOException extends Exception and is checked exception;
If you catch the IOException (checked exception), the try
block must throw that exception otherwise compilation error.

In your question tryThis() throws NumberFormatException, so
compiler recognizes this and gives error;

Confirm this!!!

Regards,
cmbhatt

[Shiva Mohan]

Thanks for the reply Chandra.Yes the question asked that tryThis() throws NumberFormatException.

So if the checkedException is caught or declared in the method,we must throw it in try block.Am i correct
[ April 20, 2007: Message edited by: Shiva Mohan ]

[Chandra Bhatt]

ShivMohan says,
So if the checkedException is caught or declared in the method,we must throw it in try block.Am i correct

Nay,
In case you declare the checked exception in the method, you need not to throw it in that, you mean by declaring that you are ducking the exception.


In case of try catch case , you are correct.

import java.io.*;
 
 
public class SampleCheck{
 
public static void main(String... args) throws IOException{

}
}

No problem with this code!!!

Regards,
cmbhatt
[ April 20, 2007: Message edited by: Chandra Bhatt ]