Question 1

An unchecked exception is an exception that must either be caught and handled or listed in the throws clause of any method that might throw or propagate it.

Accepted Answer

Unchecked exceptions, also known as runtime exceptions, do not need to be explicitly caught or listed in the throws clause. They can be handled by the caller or allowed to propagate up the call stack without warning.

Question 2

In order to have some code throw an exception, which of the following reserved words should you use?
A) throw
B) throws
C) try
D) Throwable
E) goto

Accepted Answer

The throw keyword is used to explicitly throw an exception in Java.

Question 3

Which of the following messages passed to the String str could throw a StringIndexOutOfBoundsException?
A) str length();
B) str charAt(2);
C) str replace('a', 'A');
D) str equals(str);
E) Any of these could throw a StringIndexOutOfBoundsException

Accepted Answer

The charAt() method accesses a specific character at a given index in the string. If the index is out of range (less than 0 or greater than or equal to the length of the string), it will throw a StringIndexOutOfBoundsException.

Question 4

The difference between the throw reserved word and the throws reserved word is that throw is used within a method body, while throws is used within a method header.

Accepted Answer

This statement is true. The throw keyword is used to throw an exception from within a method body, while the throws keyword is used in a method header to declare that the method may throw an exception.

Question 5

Programmers can define their own exceptions by extending the Exception class or one of the descendants of this class.

Accepted Answer

Programmers can create their own exceptions by extending the Exception class or one of its subclasses.

Question 6

If an exception is thrown and not caught anywhere in the program, then the program terminates.

Accepted Answer

When an exception is thrown and not caught anywhere in the program, it becomes an unhandled exception and causes the program to terminate.

Question 7

NullPointerExceptions and ArithmeticExceptions are both derived from which class?
A) Error
B) Exception
C) RuntimeException
D) IllegalAccessException
E) CheckedException

Accepted Answer

NullPointerExceptions and ArithmeticExceptions are both unchecked exceptions, meaning they are not required to be caught or handled by a try-catch block. The class they are derived from is RuntimeException, which is a sub-class of Exception. Error is a separate sub-class of Throwable, and IllegalAccessException is a checked exception that must be caught or declared to be thrown. Therefore, the correct choice is C, RuntimeException.

Question 8

Example Code Ch 11-1
public static void main(String[] args)
{
try
{
ExceptionThrowerCode etc = new ExceptionThrowerCode();
etc.m1();
etc.m2();
}
catch (ArithmeticException ae) { ... }
}
public class ExceptionThrowerCode
{
...
public void m1()
{
...
}
public void m2()
{
try
{
m3();
}
catch(ArithmeticException ae) {...}
catch(NullPointerException npe) {...}
}
public void m3()
{
try
{
...
}
catch(ArithmeticException ae) {...}
}
}
-Refer to Example Code Ch 11-1: If a NullPointerException arises in the try statement in m1
A) it is caught in main
B) it is caught in m1
C) it is caught in m2
D) it is caught in m3
E) it is not caught and the program terminates

Accepted Answer

The NullPointerException is not caught because there is no catch block for NullPointerException in m1 or main, and m2 is not involved in handling exceptions from m1.

Question 9

A try statement must have at least one catch statements but could have many catch statements and may or may not have a finally clause.

Accepted Answer

A try statement must have at least one catch statement to handle the exception that may occur during the execution of the try block. A try statement may have multiple catch statements to handle different types of exceptions. The finally clause is optional, and it is used to specify a block of code that will be executed regardless of whether an exception is thrown or not.

Question 10

While the Exception class is part of java.lang, IOException is part of java.io.

Accepted Answer

The Exception class is indeed part of java.lang whereas IOException is part of java.io.

Question 11

A Java program can handle an exception in several different ways. Which of the following is not a way a Java program might handle an exception?
A) ignore the exception
B) handle the exception where it arises using try and catch statements
C) propagate the exception to another method where it can be handled
D) throw the exception to a predefined Exception class to be handled
E) All of these are valid ways to handle an exception

Accepted Answer

In Java, you cannot throw an exception to a predefined Exception class to be handled. Exceptions are thrown to be caught by a try-catch block or propagated up the call stack.

Question 12

All run-time errors throw exceptions.

Accepted Answer

Not all run-time errors throw exceptions; some might result in program crashes or undefined behavior without throwing an exception, especially in languages or environments that do not support exception handling.

Question 13

If an exception arises in a catch statement, and the exception is of the type caught by the catch statement, then the catch statement catches the same exception. For instance, if the following catch statement first catches an ArithmeticException and, while executing, throws another ArithmeticException, it is able to catch the second ArithmeticException as well the first.
catch (ArithmeticException ex) {...}

Accepted Answer

A catch block cannot catch exceptions thrown from within itself. If an exception occurs in a catch block, it must be caught by another try-catch block that is either outside of the current try-catch or in a nested try-catch within the catch block.

Question 14

An exception that could also arise in the try statement that does not have an associated catch statement is
A) ClassNotFoundException
B) IllegalArgumentException
C) NegativeArraySizeException
D) NullPointerException
E) OutOfMemoryException

Accepted Answer

The answer of An exception that could also arise in...

Question 15

Example Code Ch 11-1
public static void main(String[] args)
{
try
{
ExceptionThrowerCode etc = new ExceptionThrowerCode();
etc.m1();
etc.m2();
}
catch (ArithmeticException ae) { ... }
}
public class ExceptionThrowerCode
{
...
public void m1()
{
...
}
public void m2()
{
try
{
m3();
}
catch(ArithmeticException ae) {...}
catch(NullPointerException npe) {...}
}
public void m3()
{
try
{
...
}
catch(ArithmeticException ae) {...}
}
}
-Refer to Example Code Ch 11-1: If an ArithmeticException arises in the try statement in m3
A) it is caught in main
B) it is caught in m1
C) it is caught in m2
D) it is caught in m3
E) it is not caught and the program terminates

Accepted Answer

In the method m3(), the ArithmeticException is caught within the try block itself. Therefore, it is caught in m3() before it can propagate to any outer try-catch blocks.

Question 16

An exception can produce a "call stack trace" which lists
A) the active methods in the order that they were invoked
B) the active methods in the opposite order that they were invoked
C) the values of all instance data of the object where the exception was raised
D) the values of all instance data of the object where the exception was raised and all local variables and parameters of the method where the exception was raised
E) the name of the exception thrown

Accepted Answer

A call stack trace lists the active methods in the opposite order that they were invoked, starting with the method where the exception occurred and tracing back through the methods that led up to that point.

Question 17

An ArithmeticException is a checked exception.

Accepted Answer

An ArithmeticException is an unchecked or runtime exception, not a checked exception. Checked exception is the one which is subject to a catch block or a throws clause at compile time, while unchecked or runtime exception is the one that is not required to be caught or declared in a throws clause.

Question 18

A finally clause will execute
A) only if the try statement that precedes it does not throw an exception
B) only if the try statement that precedes it throws an exception that is caught
C) only if the try statement that precedes it throws an exception that is not caught
D) only if the try statement that precedes it throws an exception, regardless of whether or not it is caught
E) in any circumstance

Accepted Answer

The finally clause in a try-catch block is designed to execute regardless of whether an exception is thrown or not, and irrespective of whether any thrown exception is caught or uncaught. It ensures that the code within the finally block is executed to perform cleanup activities like closing resources.

Question 19

Example Code Ch 11-1
public static void main(String[] args)
{
try
{
ExceptionThrowerCode etc = new ExceptionThrowerCode();
etc.m1();
etc.m2();
}
catch (ArithmeticException ae) { ... }
}
public class ExceptionThrowerCode
{
...
public void m1()
{
...
}
public void m2()
{
try
{
m3();
}
catch(ArithmeticException ae) {...}
catch(NullPointerException npe) {...}
}
public void m3()
{
try
{
...
}
catch(ArithmeticException ae) {...}
}
}
-Refer to Example Code Ch 11-1: If a NullPointerException arises in the try statement in m3
A) it is caught in main
B) it is caught in m1
C) it is caught in m2
D) it is caught in m3
E) it is not caught and the program terminates

Accepted Answer

The try statement in m2 catches both ArithmeticException and NullPointerException, so if a NullPointerException arises in m3, it will be caught in m2. Since there is no catch statement for NullPointerException in main or m1, the exception will not be caught and the program will terminate.

Question 20

An ArithmeticException is Throwable.

Accepted Answer

ArithmeticException is a subclass of java.lang.Exception which itself is a subclass of java.lang.Throwable. Therefore, ArithmeticException is also a Throwable.

Quiz 11: Exceptions

An unchecked exception is an exception that must either be caught and handled or listed in the throws clause of any method that might throw or propagate it.

In order to have some code throw an exception, which of the following reserved words should you use?

Which of the following messages passed to the String str could throw a StringIndexOutOfBoundsException?

The difference between the throw reserved word and the throws reserved word is that throw is used within a method body, while throws is used within a method header.

Programmers can define their own exceptions by extending the Exception class or one of the descendants of this class.

If an exception is thrown and not caught anywhere in the program, then the program terminates.

NullPointerExceptions and ArithmeticExceptions are both derived from which class?

A try statement must have at least one catch statements but could have many catch statements and may or may not have a finally clause.

While the Exception class is part of java.lang, IOException is part of java.io.

A Java program can handle an exception in several different ways. Which of the following is not a way a Java program might handle an exception?

All run-time errors throw exceptions.

An exception that could also arise in the try statement that does not have an associated catch statement is

An exception can produce a "call stack trace" which lists

An ArithmeticException is a checked exception.

A finally clause will execute

An ArithmeticException is Throwable.