Chapter 3 CECS Review

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

Compound

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

False

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

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

False

Decision structures are also known as selection structures.

True

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

True

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

True

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

compound

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

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):

if choice !=10:

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()

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

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

if-else

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

x is less than or equal to y

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

==

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

Control

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

Dual Alternative

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

False

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

True

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

or

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

or, and

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

relational

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

single alternative

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

!=

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

False

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

False

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

False

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

Flase

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

True

The following code snippet will change the turtle's pen size to 4 if it is presently less than 4: if turtle.pensize() < 4: turtle.pensize(4)

True

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

True

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

True

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

True 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

and

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

conditionally

The ___________ statement is used to create a decision structure

if

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()

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:

if y >= 10 and y <= 50:

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

not