Deck 11: Exception Handling

Question 1

In C#, all exceptions are objects that are members of the ____ class or one of its derived classes.

A) ApplicationException
B) Exception
C) SystemException
D) RuntimeException

Answer 1

B

Question 2

The ____ methods are used to convert string data to another data type, such as int , double , or bool , without fear of generating an exception.

A) TryData()
B) TryFromString()
C) TryParse()
D) TryConvert()

Answer 2

C

Question 3

Typically, you use the ____ block to perform clean-up tasks that must occur, regardless of whether any errors occurred or were caught.

A) default
B) always
C) execute
D) finally

Answer 3

D

Question 4

Errors you discover when compiling a program are considered to be exceptions.

Question 5

When you write a block of code in which something can go wrong, you can place the code in a(n) ____ block.

A) try
B) catch
C) finally
D) exception

Question 6

The creators of C# define an infrequent event in code as one that happens in less than ____ percent of all program executions.

A) 10
B) 25
C) 30
D) 35

Question 7

You can terminate an application with the ____ method.

A) Environment.Exit()
B) Environment.Bye()
C) Environment.Quit()
D) Environment.Terminate()

Question 8

An exception of the ____ class is thrown when an ongoing operation is aborted by the user.

A) System.InvalidOperationException
B) System.ArithmeticException
C) System.Data.OperationAbortedException
D) System.InvalidCastException

Question 9

An exception of the ____ class is thrown when an attempt is made to store an element of the wrong type within an array.

A) System.ArrayTypeMismatchException
B) System.ArithmeticException
C) System.FormatException
D) System.InvalidCastException

Question 10

____ blocks contain statements that can never execute under any circumstances because the program logic "can't get there."

A) Default
B) catch
C) finally
D) Unreachable

Question 11

The Exception class contains a read-only property named ____ that contains useful information about an Exception object.

A) StackTrace
B) Message
C) toString
D) ThrownText

Question 12

C# has more than 100 defined Exception subclasses.

Question 13

You can place any number of statements in a try block, including those you know will never throw an exception.

Question 14

Like all other classes in the C# programming language, the Exception class is a descendant of the ____ class.

A) System
B) Application
C) CLR
D) Object

Question 15

You can deliberately generate a SystemException by forcing a program to contain an error.

Question 16

The ____ block is used frequently with file input and output to ensure that open files are closed.

A) execute
B) always
C) finally
D) default

Question 17

The Exception class overrides ____ to provide a descriptive error message so a user can receive precise information about the nature of any Exception that is thrown.

A) Message()
B) StackTrace()
C) ToString()
D) ThrownMessage()

Question 18

Each ____ block can "catch" one type of Exception .

A) finally
B) catch
C) try
D) Exception

Question 19

If you are working on a professional project, Microsoft recommends that you use the general Exception class in a catch block.

Question 20

____ represents the degree to which a system is resilient to stress and able to maintain correct functioning.

A) Fault tolerance
B) Mission critical
C) Forgiveness
D) Robustness

Question 21

When an Exception object is thrown and multiple catch blocks are present, what happens?

Question 22

The memory location where the computer stores the list of locations to which the system must return is known as the ____.

A) method call
B) memory call
C) call stack
D) function call

Question 23

When you design classes containing methods that have statements that might throw exceptions, you can create the methods so they throw the Exception object but do not handle it. Why might you want to do this?

Question 24

____ is the type of exception automatically generated if there is a problem opening a file, reading data from a file, or writing to a file.

A) FileException
B) StorageException
C) FException
D) IOException

Question 25

The following example shows how a programmer might avoid a division by zero error by explicitly checking for the error condition:
if (gallonsOfGas != 0)
mpg = milesDriven /gallonsOfGas;
else mpg = 0;
Another possible way to deal with this is to use exception handling mechanisms. What factors help the programmer decide which of these methods to use?

Question 26

The StackTrace property of an Exception can be a useful debugging tool. How is this property used when debugging?

Question 27

The term ____________________ refers to any process that is crucial to an organization.

Question 28

To create your own Exception that you can throw, you can extend the ApplicationException class, which is a subclass of ____.

A) SystemException
B) Exception
C) ObjectException
D) MainException

Question 29

____________________ applications are designed so that they continue to operate, possibly at a reduced level, when some part of the system fails.

Question 30

A(n) ____________________ is any error condition or unexpected behavior in an executing program.

Question 31

When you catch an Exception , you can print the value of the ____  property to display a list of methods in the call stack so you can determine the location of the Exception .

A) StackTrace
B) CallTrace
C) MethodTrace
D) ClassTrace

Question 32

The int version of the TryParse() methods converts string data to an int . The first argument is the string that you want to convert, and the second argument is an out parameter that receives the result if the conversion is successful, or 0 if it is not. The method returns a Boolean value that indicates whether the conversion was successful. Write this method using exception handling techniques to ensure that the method returns correctly whether or not the conversion is successful. Use the method Convert.ToInt32(inputString) to do the conversion.

Question 33

Why might a finally block be necessary?

Question 34

If a finally block is associated with a try … catch pair, what are the three possible outcomes of the try that result in execution of the finally block?

Question 35

Most exceptions that are used by programmers derive from three C# classes. What are those classes?

Question 36

The system of passing an exception through a chain of calling methods is called ____ the exception.

A) propagating
B) tracing
C) stacking
D) inheriting

Question 37

The object-oriented techniques used to manage errors make up the group of methods known as ____________________.

Question 38

An exception of class _____________________________________________ is thrown when a method call is invalid for the object's current state.

Question 39

When you write a method that catches an Exception , your method does not have to handle it. Instead, you might choose to ____ the exception to the method that called your method.

A) rethrow
B) save
C) open
D) delete

Question 40

Show the syntax (the general form) of a try … catch pair.

Question 42

What types of objects can be explicitly thrown?