Question 1

An exception's default error message can be retrieved using this method.
A) getMessage()
B) getErrorMessage()
C) getDefaultMessage()
D) getDefaultErrorMessage()

Accepted Answer

The method getMessage() is used to retrieve the default error message of an exception. The other options (B, C, D) are not valid methods for this purpose.

Question 2

The numeric classes' "parse" methods all throw an exception of this type if the string being converted does not contain a convertible numeric value.
A) NumberFormatException
B) ParseIntError
C) ExceptionMessage
D) FileNotFoundException

Accepted Answer

The NumberFormatException is the standard exception thrown by the parse methods of the numeric classes when the string being converted does not contain a convertible numeric value. Choice B (ParseIntError) and D (FileNotFoundException) are not valid options because they are not related to numeric parsing. Choice C (ExceptionMessage) is not a real exception type.

Question 3

To write data to a binary file you create objects from the following classes:
A) File and PrintWriter
B) File and Scanner
C) FileOutputStream and DataOutputStream
D) BinaryFileWriter and BinaryDataWriter

Accepted Answer

The FileOutputStream class allows you to create a stream of bytes to write to a file, while the DataOutputStream class allows you to write data in various primitive data types (such as int, double, boolean) to the file. This makes it the best choice for writing data to a binary file. Option A and B use classes that are used for writing text files, so they are not suitable for writing to binary files. Option D is not a valid choice as there is no such class as BinaryFileWriter or BinaryDataWriter in Java.

Question 4

What is demonstrated by the following code?
Try
{
(try block statements . . .)
}
Catch(NumberFormatException | IOException ex)
{
RespondToError();
}
A) Multi-catch, a catch clause that can handle more than one exception, beginning in Java 7
B) A catch clause that can handle either exception type, but not both
C) A conditional catch clause prototype that uses an overloaded OR operator to bind exception types
D) This code is not supported in any version of Java, an error will result.

Accepted Answer

The code demonstrates the use of multi-catch, a feature introduced in Java 7 that allows a single catch block to handle multiple types of exceptions. In this case, the catch block can handle both NumberFormatException and IOException exceptions.

Question 5

If, within one try statement you want to have catch clauses of the following types, in which order should they appear in your program: (1) Exception
(2) IllegalArgumentException
(3) RuntimeException
(4) Throwable
A) 1, 2, 3, 4
B) 2, 3, 1, 4
C) 4, 1, 3, 2
D) 3, 1, 2, 4

Accepted Answer

When writing catch clauses, it is important to order them from most specific to least specific. IllegalArgumentException and RuntimeException are both subclasses of Exception, so they should come after Exception in the catch block. Throwable should be the last catch block since it is the parent class of all exceptions. Therefore, the correct order is (2) IllegalArgumentException, (3) RuntimeException, (1) Exception, (4) Throwable, which corresponds to choice B.

Question 6

All exceptions are instances of classes that extend this class.
A) RunTimeException
B) Throwable
C) Error
D) Exception

Accepted Answer

All exceptions are instances of classes that extend the Throwable class. The Throwable class is the superclass of all errors and exceptions in the Java language.

Question 7

If your code does not handle and exception when it is thrown, this prints an error message and crashes the program.
A) Java error handler
B) multi-catch
C) default exception handler
D) try statement

Accepted Answer

The default exception handler in Java is responsible for printing an error message and crashing the program when an exception is thrown and not handled by any other exception handler.

Question 8

Given the following constructor code, which of the statements are TRUE?
Public Book(String ISBNOfBook, double priceOfBook,
Int numberOrderedOfBook)
{
If (ISBNOfBook == "")
Throw new BlankISBN();
If (priceOfBook < 0)
Throw new NegativePrice(priceOfBook);
If (numberedOrderedOfBook < 0)
Throw new NegativeNumberOrdered(numberOrderedv);
ISBN = ISBNOfBook;
Price = priceOfBook;
NumberedOrdered = numberOrderedOfBook;
}
A) There is an error: a throws clause should be added to the constructor header.
B) Classes extending the Exception class should be created for each of the custom exceptions that are thrown in the constructor.
C) The calling method must handle the exceptions thrown in the constructor, or have its own throws clause specifying them.
D) All of the above

Accepted Answer

A) There is an error in the code, as a throws clause should be added to the constructor header to specify the exceptions that can be thrown by the constructor.
B) Classes extending the Exception class must be created for each of the custom exceptions that are thrown in the constructor, such as BlankISBN, NegativePrice, and NegativeNumberOrdered.
C) The calling method must handle the exceptions thrown in the constructor, or have its own throws clause specifying them, to ensure proper error handling and prevent unexpected program termination.

Question 9

If the code in a method can potentially throw a checked exception, then that method must:
A) handle the exception
B) have a throws clause listed in the method header
C) neither A nor B
D) either A or B

Accepted Answer

If a method can potentially throw a checked exception, then it must either handle the exception (using a try/catch block) or declare the exception using a throws clause in the method header. Therefore, either A or B must be present in the method.

Question 10

A(n) ________ is an object that is generated in memory as the result of an error or an unexpected event.
A) exception handler
B) exception
C) default exception handler
D) error message

Accepted Answer

An exception is an object that is generated in memory as the result of an error or an unexpected event. Exception handling is the process of detecting and responding to exceptions in a program. The other options are not appropriate definitions of an exception.

Question 11

To read data from a binary file you create objects from the following classes:
A) FileInputStream and DataInputStream
B) File and PrintWriter
C) File and Scanner
D) BinaryFileReader and BinaryDataReader

Accepted Answer

The FileInputStream class provides a way to read data from a binary file, while DataInputStream class provides methods to read primitive data types from the input stream created by FileInputStream. Therefore, choice A is the best option for reading data from a binary file.

Question 12

All of the exceptions that you will handle are instances of classes that extend this class.
A) RunTimeException
B) IOException
C) Error
D) Exception

Accepted Answer

The class Exception is the parent class of all other exception classes, including RuntimeException and IOException. Thus, by catching Exception, we can handle any possible exception that may be thrown in the program.

Question 13

The IllegalArgumentException class extends the RuntimeException class, and is therefore:
A) a checked exception class
B) an unchecked exception class
C) never used directly
D) none of the above

Accepted Answer

The IllegalArgumentException class is an unchecked exception class, meaning it does not need to be declared in a method's throws clause or handled explicitly. It is often used to indicate that an invalid or inappropriate argument has been passed to a method.

Question 14

The ability to catch multiple types of exceptions with a single catch is known as ________, and was introduced in Java 7.
A) multi-catch
B) super catch
C) exception trapping
D) compound catch

Accepted Answer

Multi-catch allows a single catch block to handle multiple types of exceptions by specifying the exceptions as a list separated by pipe symbols. It was introduced in Java 7. The other options (B, C, D) are not valid terms or concepts in Java exception handling.

Question 15

In a try/catch construct, after the catch statement is executed:
A) the program returns to the statement following the statement in which the exception occurred
B) the program terminates
C) the program resumes at the statement that immediately follows the try/catch construct
D) the program resumes at the first statement of the try statement

Accepted Answer

After the catch statement is executed, the program resumes at the statement that immediately follows the try/catch construct, not at the point where the exception occurred or at the beginning of the try block.

Question 16

In the following code, assume that inputFile references a Scanner object that has been successfully used to open a file: double totalIncome = 0.0;
While (inputFile.hasNext())
{
Try
{
TotalIncome += inputFile.nextDouble();
}
Catch(InputMismatchException e)
{
System.out.println("Non-numeric data encountered " +
"in the file.");
InputFile.nextLine();
}
Finally
{
TotalIncome = 35.5;
}
}
What will be the value of totalIncome after the following values are read from the file?
2)5
8)5
3)0
5)5
Abc
1)0
A) 19.5
B) 0.0
C) 35.5
D) 75.0

Accepted Answer

The `finally` block sets `totalIncome` to 35.5 after each iteration, overriding any additions made in the try block.

Question 17

When an exception is thrown:
A) it must always be handled by the method that throws it
B) the program terminates even if the exception is handled
C) it must be handled by the program or by the default exception handler
D) it may be ignored

Accepted Answer

When an exception is thrown, it must be handled by the program or by the default exception handler. Ignoring the exception can lead to unexpected and undesirable behavior in the program. However, it is not always necessary for the method that throws the exception to handle it. Other methods or components of the program can catch and handle the exception. The program does not necessarily terminate if the exception is handled properly.

Question 18

The following catch statement can: catch (Exception e) {…}
A) handle all exceptions that are instances of the Exception class, but not a subclass of Exception
B) handle all throwable objects by using polymorphic reference as a parameter in the catch clause
C) handle all exceptions that are instances of the Exception class or a subclass of Exception
D) is an error since no objects are instantiated in the Exception class

Accepted Answer

The catch statement with the parameter Exception e will handle all exceptions that are instances of the Exception class or a subclass of Exception. This includes checked exceptions such as IOException and unchecked exceptions such as NullPointerException. This catch block is a general catch block that can handle a wide range of exceptions.

Question 19

Why does the following code cause a compiler error?
Try
{
Number = Integer.parseInt(str);
}
Catch (IllegalArgumentException e)
{
System.out.println("Bad number format.");
}
Catch (NumberFormatException e)
{
System.out.println(str + " is not a number.");
}
A) Because you can have only one catch clause in a try statement
B) Because NumberFormatException inherits from IllegalArgumentException. The code should handle NumberFormatException before IllegalArgumentException
C) Because the Integer.parseInt method does not throw a NumberFormatException
D) Because the Integer.parseInt method does not throw an IllegalArgumentException

Accepted Answer

NumberFormatException is a subclass of IllegalArgumentException, therefore the catch clause for NumberFormatException should be before the catch clause for IllegalArgumentException.

Question 20

The exception classes are in packages in the ________.
A) Java API
B) JVM
C) Compiler
D) Ex class

Accepted Answer

The Java API (Application Programming Interface) includes predefined exception classes in various packages, such as java.lang, java.io, and java.net. These exception classes can be used by Java applications to handle different types of errors or exceptional situations that may occur during program execution. The JVM (Java Virtual Machine) and Compiler are not directly related to the definition or use of exception classes. "Ex class" is not a relevant term in the context of Java exception handling.

Quiz 11: Exceptions and Advanced File IO

An exception's default error message can be retrieved using this method.

The numeric classes' "parse" methods all throw an exception of this type if the string being converted does not contain a convertible numeric value.

To write data to a binary file you create objects from the following classes:

What is demonstrated by the following code? Try { (try block statements . . .) } Catch(NumberFormatException | IOException ex) { RespondToError() ; }

If, within one try statement you want to have catch clauses of the following types, in which order should they appear in your program: (1) Exception (2) IllegalArgumentException (3) RuntimeException (4) Throwable

All exceptions are instances of classes that extend this class.

If your code does not handle and exception when it is thrown, this prints an error message and crashes the program.

If the code in a method can potentially throw a checked exception, then that method must:

A(n) ________ is an object that is generated in memory as the result of an error or an unexpected event.

To read data from a binary file you create objects from the following classes:

All of the exceptions that you will handle are instances of classes that extend this class.

The IllegalArgumentException class extends the RuntimeException class, and is therefore:

The ability to catch multiple types of exceptions with a single catch is known as ________, and was introduced in Java 7.

In a try/catch construct, after the catch statement is executed:

When an exception is thrown:

The following catch statement can: catch (Exception e) {…}

Why does the following code cause a compiler error? Try { Number = Integer.parseInt(str) ; } Catch (IllegalArgumentException e) { System.out.println("Bad number format.") ; } Catch (NumberFormatException e) { System.out.println(str + " is not a number.") ; }

The exception classes are in packages in the ________.