2210 Chapter 3 Quick Study

Front 1

What control can be used to gather text input from the user?

Back 1

A TextBox control

Front 2

In code, how do you retrieve data that has been typed into a TextBox control?

Back 2

Retrieve the contents of the control’s Text property

Front 3

What type of data does a control’s Text property always contain?

Back 3

A string

Front 4

How do you clear the contents of a TextBox control?

Back 4

Assign an empty string ( "" ) to the Text property.

Front 5

What is the purpose of a variable?

Back 5

To store a value in memory

Front 6

Give an example of a variable declaration that will store the name of your favorite
food.

Back 6

string myFavoriteFood = "pizza";

Front 7

For each of the following items, determine whether the data type should be an
integer, string, or real number.
a. pet name
b. sales tax
c. mailing address
d. video game score

Back 7

a. String
b. Real number
c. String
d. Integer

Front 8

Indicate whether each of the following is a legal variable name. If it is not, explain
why.
a. pay_Rate
b. speed of sound
c. totalCost
d. 2ndPlaceName

Back 8

a. Legal
b. Illegal; spaces are not allowed in variable names.
c. Legal
d. Illegal; first character of the variable name cannot be a number.

Front 9

What will be stored in the message variable after the following statement is
executed?
string message = "He" + "ll" + "o!";

Back 9

The string "Hello!"

Front 10

What is the lifetime of a variable that is declared inside of a Click event handler?

Back 10

While the event is executing; then it is deleted.

Front 11

Assuming the variable greeting has not been assigned a value, what will be the
result of the following statement?
MessageBox.Show(greeting);

Back 11

The statement will result in an error.

Front 12

Will the following statement cause an error? Why or why not?
string luckyNumber = 7;

Back 12

Yes, string variables can be assigned only string values.

Front 13

Write a single declaration statement for the variables name , city , and state .

Back 13

string name, city, state;

Front 14

Specify the appropriate primitive numeric data type to use for each of the following
values.
a. 24 dollars
b. 12 bananas
c. 14.5 inches
d. 83 cents
e. 2 concert tickets

Back 14

a. decimal
b. int
c. double
d. decimal
e. int

Front 15

Which of the following variable declarations will cause an error? Why?
a. decimal payRate = 24m;
b. int playerScore = 1340.5;
c. double boxWidth = 205.25;
d. string lastName = "Holm";

Back 15

b, variables of the int data type can be assigned only whole-number values.

Front 16

Write a programming statement that will convert the following decimal variable
to an int and store the result in an int variable named dollars :
decimal deposit = 976.54m;

Back 16

int dollars = (int)deposit;

Front 17

What value will the wholePieces variable contain after the following code
executes?
double totalPieces = 6.5;
int wholePieces = (int)totalPieces;

Back 17

6

Front 18

List the operands for the following math expression.
length * width

Back 18

length and width

Front 19

Summarize the mathematical order of operations.

Back 19

1. Perform any operations that are enclosed in parentheses.
2. Perform any multiplications, divisions, or modulus operations as they appear
from left to right
3. Perform any additions or subtractions as they appear from left to right.

Front 20

Rewrite the following code segment so that it does not cause an error.
decimal pricePerFoot = 2.99m;
double boardLength = 10.5;
decimal totalCost = boardLength * pricePerFoot;

Back 20

decimal pricePerFoot = 2.99m;
decimal boardLength = 10.5;
decimal totalCost = boardLength * pricePerFoot;
or
decimal pricePerFoot = 2.99m;
double boardLength = 10.5;
decimal totalCost = (decimal)boardLength * pricePerFoot;

Front 21

Assume result is a double variable. When the following statement executes,
what value will be stored in result ?
result = 4 + 10 / 2;

Back 21

9

Front 22

Assume result is an int variable. When the following statement executes, what
value will be stored in result ?
result = (2 + 5) * 10;

Back 22

70

Front 23

Assume result is a double variable. When the following statement executes,
what value will be stored in result ?
result = 5 / 2;

Back 23

2.5

Front 24

Rewrite the following statements using combined assignment operators:
a. count = count + 1;
b. amount = amount – 5;
c. radius = radius * 10 ;
d. length = length / 2;

Back 24

a. count += 1;
b. amount −= 5;
c. radius *= 10 ;
d. length /= 2;

Front 25

What method converts the string literal "40" to a value of the int data type?

Back 25

int.Parse

Front 26

Write a statement that converts each of the following string values to the decimal
data type using the decimal.Parse method.
a. "9.05"
b. grandTotal
c. "50"
d. priceTextBox.Text

Back 26

a. decimal.Parse("90.5");
b. decimal.Parse(grandTotal);
c. decimal.Parse("50");
d. decimal.Parse(priceTextBox.Text);

Front 27

Suppose an application has a decimal variable named total and a Label control
named totalLabel . What will be the result when the following assignment
statement is executed?
totalLabel.Text = total;

Back 27

The result will be an error because numeric values cannot be assigned to
strings.

Front 28

Write a statement that displays each of the following numeric variables in a
message box.
a. grandTotal
b. highScore
c. sum
d. width

Back 28

a. MessageBox.Show(grandTotal.ToString());
b. MessageBox.Show(highScore.ToString());
c. MessageBox.Show(sum.ToString());
d. MessageBox.Show(width.ToString());

Front 29

Write a statement that will store the value of an int variable named result in the
Text property of a Label control named resultLabel .

Back 29

resultLabel.Text = result.ToString();

Front 30

Write a programming statement that displays the string value of a variable named
salary in a message box using currency format.

Back 30

MessageBox.Show(salary.ToString("c"));

Front 31

The following variable names give an indication of the data each stores. For each
variable, specify the format string that you think is most appropriate.
a. discountPercentage
b. atomicWeight
c. retailPrice
d. quantityPurchased
e. degreesKelvin

Back 31

a. "P" or "p" for percent format
b. "E" or "e" for exponential scientific format
c. "C" or "c" for currency format
d. "N" or "n" for number format
e. "F" or "f" for fixed-point scientific format

Front 32

What value will be displayed in the message box when the following code segment
is executed?
double apples = 12.0;
MessageBox.Show(apples.ToString("n0"));

Back 32

12

Front 33

Examine the following integer variables and specify the number of leading zeros to
use with the d or D format strings so that all the numbers are equal in width.
int valueA = 234, valueB = 56, valueC = 7, valueD = 89123;

Back 33

"d5"

Front 34

Write a programming statement that uses the ToString method of a variable
named millimeters so that it displays a precision of four digits after the decimal
point in fixed-point scientific format.

Back 34

millimeters.ToString("f4");

Front 35

What can cause an application to throw an exception?

Back 35

An unexpected error that occurs while a program is running, such as user input
that is not in the correct format

Front 36

How do you get out of break mode when an exception is thrown?

Back 36

Click the Stop Debugging button or by pressing shift+F5

Front 37

What kind of code does the try block of a try - catch statement contain?

Back 37

Statements that can potentially throw an exception

Front 38

What causes the program to jump to the catch clause and execute the catch block
of a try - catch statement?

Back 38

If a statement in the try block throws an exception

Front 39

How can you display the default error message when an exception is thrown?

Back 39

Assign a name to the exception object when writing the catch clause of
a try-catch statement and then use the Message property of the
exception object in the catch block to display the default error message
in a message box.

Front 40

Write a try - catch statement for an application that calculates the sum of two
whole numbers and displays the result. The application uses two TextBox controls
named value1TextBox and value2TextBox to gather the input and a Label
control named sumLabel to display the result.

Back 40

try
{
int value1; // To hold value 1.
int value2; // To hold value 2.
int sum; // To hold the sum.
// Get the values as input from the user.
value1 = int.Parse(value1TextBox.Text);
value2 = int.Parse(value2TextBox.Text);
// Calculate the sum of value 1 and value 2.
sum = value1 + value2;
// Display the result in the Label control.
sumLabel.Text = sum.ToString();
}
catch (Exception ex)
{
// Display the default error message.
MessageBox.Show(ex.Message);
}

Front 41

What are two advantages of using named constants?

Back 41

They make programs more self-explanatory and allow for widespread changes to
easily be made to the program.

Front 42

Write a programming statement that declares a named constant for a 10 percent
discount.

Back 42

const double DISCOUNT = 0.9;

Front 43

Where should you place field declarations in a program?

Back 43

At the top of a class declaration, before any methods

Front 44

What access modifier should you use when declaring a field? Why?

Back 44

It’s a good programming practice to make fields private because private fields
are hidden from code outside the class. That prevents code outside the class from
changing the values of a class’s fields and helps prevent bugs from creeping into
your program.

Front 45

How is the lifetime of a field different from the lifetime of a local variable?

Back 45

A local variable exists only while the method in which it is declared is executing,
but a field exists as long as the form exists.

Front 46

Write a programming statement that declares a constant field for a 5.9 percent
interest rate.

Back 46

private const decimal INTEREST_RATE = 0.059m;

Front 47

Write a programming statement that uses the Math.Pow method to square the
number 12 and store the result in a double variable named product .

Back 47

double product = Math.Pow(12.0, 2.0);

Front 48

What method of the Math class can be used to determine the larger of two
values?

Back 48

Math.Max

Front 49

What method of the Math class can be used to determine the smaller of two
values?

Back 49

Math.Min

Front 50

What happens if you press the Enter key while a Button control has the focus?

Back 50

The button’s Click event handler will execute.

Front 51

How do you display a form in tab order selection mode? How do you exit tab
order selection mode?

Back 51

Click View on the Visual Studio menu bar and then click Tab Order . Exit tab
order selection mode by pressing the Esc key.

Front 52

Write a programming statement that gives the focus to a TextBox control named
numberTextBox .

Back 52

numberTextBox.Focus();

Front 53

How do you assign an access key to a Button control?

Back 53

In the Text property, place an ampersand (&) before the character you wish to
use as the access key.

Front 54

How do you display an ampersand (&) character on a Button control?

Back 54

In the Text property, place two ampersand (&&) characters where you would
like the single ampersand to appear on the Button control.

Front 55

Write the code that will change the BackColor property of a Label control named
resultLabel to the color white and the ForeColor property to the color red.

Back 55

resultLabel.BackColor = Color.White;
resultLabel.ForeColor = Color.Red;

Front 56

List the different values of a form’s BackgroundImageLayout property.

Back 56

None, Tile, Center, Stretch, and Zoom

Front 57

When a GroupBox control is deleted, what happens to the controls that are inside?

Back 57

The controls inside the GroupBox control are also deleted.

Front 58

How are the TabIndex properties of the controls inside the group box organized?

Back 58

The TabIndex values of controls inside a group box are organized relative to the
GroupBox control’s TabIndex property.

Front 59

How is a Panel control different from a GroupBox control?

Back 59

A Panel cannot display a title and does not have a Text property. A Panel’s
border can be specified by its BorderStyle property.