Chapter 3

An action in a single alternative decision structure is performed only when the condition is true.

T

What is the result of the following Boolean expression, given that x = 5, y = 3, and z = 8? x < y or z > x a. True b. False c. 8 d. 5

b. False

What does the following expression mean? x <= y a. x is less than y b. x is less than or equal to y c. x is greater than y d. x is greater than or equal to y

b. x is less than or equal to y

The decision structure that has two possible paths of execution is known as a. single alternative b. double alternative c. dual alternative d. two alternative

c. dual alternative

Which logical operators perform short-circuit evaluation? a. or, not b. not, and c. or, and d. and, or, not

c. or, and

n Python the __________ symbol is used as the not-equal-to operator. a. == b. <> c. <= d. !=

d. !=

Python provides a special version of a decision structure known as the __________ statement, which makes the logic of the nested decision structure simpler to write.

if-elif-else

A(n) __________ decision structure provides only one alternative path of execution.

single alternative

Decision structures are also known as selection structures.

T

Expressions that are tested by the if statement are called Boolean expressions.

T

Nested decision statements are one way to test more than one condition.

T

The if statement causes one or more statements to execute only when a Boolean expression is true.

T

Python allows you to compare strings, but it is not case sensitive.

F

The turtle.isdown() function returns ___________ if the turtle's pen is down.

True

What is the result of the following Boolean expression, given that x = 5, y = 3, and z = 8? x < y and z > x a. True b. False c. 8 d. 5

b. False

What is the result of the following Boolean expression, given that x = 5, y = 3, and z= 8? not (x < y or z > x) and y < z a. True b. False c. 8 d. 5

b. False

In a decision structure, the action is ___________ executed because it is performed only when a specific condition is true.

conditionally

In flowcharting, the __________ symbol is used to represent a Boolean expression.

diamond

Boolean variables are commonly used as __________ to indicate whether a specific condition exists.

flags

A(n) __________ statement will execute one block of statements if its condition is true or another block if its condition is false.

if-else

A(n) __________ operator determines whether a specific relationship exists between two values.

relational

In Python the __________ symbol is used as the equality operator. a. == b. <> c. <= d. !=

a. ==

Python uses the same symbols for the assignment operator as for the equality operator.

F

Short -circuit evaluation is only performed with the not operator.

F

The Python language is not sensitive to block structuring of code.

F

The following statement will check to see if the turtle's pen color is 'green': if turtle.pencolor() = 'green'

F

The not operator is a unary operator which must be used in a compound expression.

F

Which of the following is the correct if clause to determine whether choice is anything other than 10? a. if choice != 10: b. if choice != 10 c. if choice <> 10: d. if not(choice < 10 and choice > 10):

a. if choice != 10:

When using the __________ logical operator, one or both of the subexpressions must be true for the compound expression to be true. a. or b. and c. not d. maybe

a. or

A Boolean variable can reference one of two values which are a. yes or no b. True or False c. T or F d. Y or N

b. True or False

When using the __________ logical operator, both subexpressions must be true for the compound expression to be true. a. or b. and c. not d. either or or and

b. and

A(n) __________ structure is a logical design that controls the order in which a set of statements execute. a. function b. control c. sequence d. iteration

b. control

Multiple Boolean expressions can be combined by using a logical operator to create __________ expressions. a. sequential b. logical c. compound d. mathematical

c. compound

Which of the following will determine if the turtle's pen is up and will change it to down if that is the case? a. if turtle.isup(): turtle.isdown() b. if turtle.isdown turtle.penup() c. if not(turtle.isdown()): turtle.pendown() d. if not(turtle.penup()) turtle.penup()

c. if not(turtle.isdown()): turtle.pendown()

Which of the following is the correct if clause to determine whether y is in the range 10 through 50, inclusive? a. if 10 < y or y > 50: b. if 10 > y and y < 50: c. if y >= 10 and y <= 50: d. if y >= 10 or y <= 50:

c. if y >= 10 and y <= 50:

A(n) ___________ expression is made up of two or more Boolean expressions.

compound

Which of the following will hide the turtle if it is visible? a. if turtle.isvisible(): turtle.invisible() b. if turtle.isvisible turtle.hideturtle() c. turtle.isvisible(): turtle.hide() d. if turtle.isvisible(): turtle.hideturtle()

d. if turtle.isvisible(): turtle.hideturtle()

The ___________ statement is used to create a decision structure.

if

The logical __________ operator reverses the truth of a Boolean expression.

not