Chapter 4: Making Decisions

TRUE/FALSE

1. Every decision you make in a
computer program involves evaluating a Boolean expression.

2. When you need to satisfy two or more
criteria to initiate an event in a program, you must make sure that the second
decision is made entirely independently of the first decision.

3. Most programming languages allow you
to ask two or more questions in a single comparison.

4. When you combine AND and OR
operators, the OR operators take precedence, meaning their Boolean values are
evaluated first.

5. You can use parentheses to override
the default order of operations.

MULTIPLE CHOICE

1. A selection with an action that is
associated with each of two possible outcomes is known as a(n) ____ selection.

a. unary c. octal

b. binary d. semiconductor

2. The keyword that is NOT included in
a single-alternative selection is ____.

a. if c. else

b. then d. endif

3. Boolean expressions are named after
____.

a. Harold
Boolean c. George
Boole

b. Henry
Boole d. Gerhardt Boolean

4. ____ operators require two operands.

a. Unary c. Binary

b. Tertiary d. Double

5. In most programming languages, the
____ sign means “greater than.”

a. < c. <=

b. = d. >

6. Usually, ____ variables are not
considered to be equal unless they are identical.

a. string c. character

b. integers d. floating point

7. When you ask multiple questions
before an outcome is determined, you create a ____ condition.

a. dual-alternative c. single-alternative

b. nested d. compound

8. A(n) ____ decision is a decision in
which two conditions must be true for an action to take place.

a. OR c. AND

b. XOR d. OR-ELSE

9. A series of nested if statements is
also called a ____ statement.

a. n-alternative
if c. case

b. cascading
if d. loop

10. A series of nested if statements is
also called a ____ if statement.

a. stacked c. bonded

b. cascading d. hooked

11. Most languages allow you to use a
variation of the decision structure called the ____ structure when you must
nest a series of decisions about a single variable.

a. blocked c. AND IF

b. case d. logical

12. Most programming languages allow you
to ask two or more questions in a single comparison by using an ____ operator
that joins decisions in a single statement.

a. AND c. IF

b. OR d. XOR

13. When creating a truth table, you must
determine how many possible Boolean value combinations exist for the
conditions. If there are two conditions, ____ combinations will exist.

a. 2 c. 8

b. 4 d. 16

14. In a truth table, the expression ____
is true.

a. true AND
true c. false
AND true

b. true AND
false d. false
AND false

15. The conditional AND operator in Java,
C++, and C# is ____.

a. & c. **

b. AND d. &&

16. ____ are diagrams used in mathematics
and logic to help describe the truth of an entire expression based on the truth
of its parts.

a. Decision
matrices c. Truth diagrams

b. Decision
diagrams d. Truth tables

17. For maximum efficiency, a good rule of
thumb in an OR decision is to ____.

a. first ask
the question that is more likely to be true

b. first ask
the question that is more likely to be false

c. rewrite
as an AND decision and ask the question more likely to be true

d. rewrite
as an AND decision and ask the question more likely to be false

18. C#, C++, C, and Java use the symbol
____ as the logical OR operator.

a. % c. ||

b. $ d. ^

19. You use the logical ____ operator to
reverse the meaning of a Boolean expression.

a. AND c. OR

b. XOR d. NOT

20. The logical AND operator can be
compared to ____ in terms of precedence.

a. addition c. multiplication

b. subtraction d. division

21. The logical OR operator can be
compared to ____ in terms of precedence.

a. addition c. multiplication

b. subtraction d. division

COMPLETION

1. A dual-alternative, or
____________________, selection is one in which an action is associated with
each of two possible outcomes.

2. The ____________________ clause of
the decision is the part of the decision that holds the action or actions that
execute when the tested condition in the decision is true.

3. When you ____________________
decisions because the resulting action requires that two conditions be true,
you must decide which of the two decisions to make first.

4. In an AND decision, first ask the
question that is less likely to be ____________________.

5. When you use a(n)
____________________ check, you compare a variable to a series of values that
mark the limiting ends of ranges.

MATCHING

Match each item with a statement below.

a. nested
decision f. logical OR

b. case structure g. else
clause

c. AND h. dead

d. binary
selection i. trivial expressions

e. Boolean
expression

1. if-then-else structure

2. An expression whose value can be
only true or false

3. Part of a decision that executes
only when the tested condition in the decision is false

4. Will always evaluate to the same
result

5. Path that can never be traveled

6. A decision “inside of” another
decision

7. Used when you must nest a series of
decisions about a single variable

8. Using this operator, each Boolean
expression must be true in order for the entire expression to be evaluated as
true

9. When this operator is used, only one
of the listed conditions must be met for the resulting action to take place

SHORT ANSWER

1. Describe a Boolean expression.

2. Who was George Boole and what did he
do?

3. List the three types of comparisons
that enable the making of any decision.

4. When would you use a negative
comparison?

5. How can you improve the efficiency
of a nested decision?

6. Explain the purpose and use of the
AND operator.

7. In an OR decision, why is it more
efficient to first ask the question that is more likely to be true?

8. Explain what a range check is and
provide an example.

9. When you combine AND and OR
operators within the same statement, which takes precedence?

10. List three techniques to avoid
confusion when mixing AND and OR operators.