Deck 4: Control Structures I (Selection)

Question 1

Suppose that x is an int variable.Which of the following expressions always evaluates to true?

A) (x > 0) || ( x <= 0)
B) (x >= 0) || (x == 0)
C) (x > 0) && ( x <= 0)
D) (x > 0) && (x == 0)

Answer 1

A

Question 2

Suppose P and Q are logical expressions.The logical expression P && Q is true if both P and Q are true.

Answer 2

True

Question 3

The expression (x >= 0 && x <= 100)evaluates to false if either x < 0 or x >= 100.

Answer 3

False

Question 4

Which of the following is the "not equal to" relational operator?

A) !
B) |
C) !=
D) &

Question 5

The result of a logical expression cannot be assigned to an int variable,but it can be assigned to a bool variable.

Question 6

The operators != and == have the same order of precedence.

Question 7

The expression in an if statement is sometimes called a(n)____.

A) selection statement
B) action statement
C) decision maker
D) action maker

Question 8

If the expression in an assert statement evaluates to true,the program terminates.

Question 9

Suppose x is 5 and y is 7.Choose the value of the following expression: (x != 7)&& (x <= y)

A) false
B) true
C) 0
D) null

Question 10

In a ____ control structure,the computer executes particular statements depending on some condition(s).

A) looping
B) repetition
C) selection
D) sequence

Question 11

Which of the following is a relational operator?

A) =
B) ==
C) !
D) &&

Question 12

What does <= mean?

A) less than
B) greater than
C) less than or equal to
D) greater than or equal to

Question 13

Which of the following expressions correctly determines that x is greater than 10 and less than 20?

A) 10 < x < 20
B) (10 < x < 20)
C) 10 < x && x < 20
D) 10 < x || x < 20

Question 14

Which of the following operators has the highest precedence?

A) !
B) *
C) %
D) =

Question 15

In C++,!,&&,and || are called relational operators.

Question 16

In C++,both ! and != are relational operators.

Question 17

A compound statement functions as if it was a single statement.

Question 18

Which of the following operators has the lowest precedence?

A) !
B) ||
C) &&
D) =

Question 19

A control structure alters the normal sequential flow of execution in a program.

Question 20

In C++,&& has a higher precedence than ||.

Question 21

Assume you have three int variables: x = 2,y = 6,and z.Choose the value of z in the following expression: z = (y / x > 0)? x : y;.

A) 2
B) 3
C) 4
D) 6

Question 22

What is the output of the following code? if (6 > 8)
{
Cout << " ** " << endl ;
Cout << "****" << endl;
}
Else if (9 == 4)
Cout << "***" << endl;
Else
Cout << "*" << endl;

A) *
B) **
C) ***
D) ****

Question 23

The appearance of = in place of == resembles a(n)____.

A) syntax error
B) silent killer
C) compilation error
D) input failure

Question 24

What is the output of the following C++ code? int x = 35;
Int y = 45;
Int z;
If (x > y)
Z = x + y;
Else
Z = y - x;
Cout << x << " " << y << " " << z << endl;

A) 35 45 80
B) 35 45 10
C) 35 45 -10
D) 35 45 0

Question 25

The conditional operator ?: takes ____ arguments.

A) two
B) three
C) four
D) five

Question 26

Putting ____________________ in front of a logical expression reverses the value of that logical expression.

Question 27

Which of the following will cause a logical error if you are attempting to compare x to 5?

A) if (x == 5)
B) if (x = 5)
C) if (x <= 5)
D) if (x >= 5)

Question 28

To develop a program,you can use an informal mixture of C++ and ordinary language,called ____.

A) assert code
B) pseudocode
C) cppcode
D) source code

Question 29

What is the output of the following C++ code? int x = 55;
Int y = 5;
Switch (x % 7)
{
Case 0:
Case 1:
Y++;
Case 2:
Case 3:
Y = y + 2;
Case 4:
Break;
Case 5:
Case 6:
Y = y - 3;
}
Cout << y << endl;

A) 2
B) 5
C) 8
D) 10

Question 30

What is the value of x after the following statements execute? int x;
X = (5 <= 3 && 'A' < 'F')? 3 : 4

A) 2
B) 3
C) 4
D) 5

Question 31

When one control statement is located within another,it is said to be ____.

A) blocked
B) compound
C) nested
D) closed

Question 32

For a program to use the assert function,it must include which of the following?

A) #include <assert>
B) #include <cassert>
C) #include <assertc>
D) #include NDEBUG

Question 33

What is the output of the following code? char lastInitial = 'A';
Switch (lastInitial)
{
Case 'A':
Cout << "section 1" <Break;
Case 'B':
Cout << "section 2" <Break;
Case 'C':
Cout << "section 3" <Break;
Case 'D':
Cout << "section 4" <Break;
Default:
Cout << "section 5" <}

A) section 1
B) section 2
C) section 3
D) section 5

Question 34

The symbol > is a(n)____________________ operator.

Question 35

What is the output of the following code? char lastInitial = 'S';
Switch (lastInitial)
{
Case 'A':
Cout << "section 1" <Break;
Case 'B':
Cout << "section 2" <Break;
Case 'C':
Cout << "section 3" <Break;
Case 'D':
Cout << "section 4" <Break;
Default:
Cout << "section 5" <}

A) section 2
B) section 3
C) section 4
D) section 5

Question 36

You can disable assert statements by using which of the following?

A) #include
B) #define
C) #clear NDEBUG
D) #define NDEBUG

Question 37

What is the output of the following code fragment if the input value is 4? int num;
Int alpha = 10;
Cin >> num;
Switch (num)
{
Case 3:
Alpha++;
Break;
Case 4:
Case 6:
Alpha = alpha + 3;
Case 8:
Alpha = alpha + 4;
Break;
Default:
Alpha = alpha + 5;
}
Cout << alpha << endl;

A) 13
B) 14
C) 17
D) 22

Question 38

A ____________________ operator allows you to make comparisions in a program.

Question 39

In C++,the logical operator AND is represented by ____________________.

Question 40

The value of the expression 7 + 8 <= 15 is ____________________.

Question 41

The ____________________ of relational and logical operators is said to be from left to right.

Question 42

Suppose found = true and num = 6.The value of the expression (!found)|| (num > 6)is ____________________.

Question 43

A(n)____________________ structure does not require the evaluation of a logical expression.

Question 44

Consider the following statements.
int score;
string grade;
if (score >= 65)
grade = "pass";
else
grade = "fail";
If score is equal to 75,the value of grade is "____________________".

Question 45

Every else must be paired with a(n)____________________.

Question 46

The value of the expression 6 < 5 || 'g' > 'a' && 7 < 4
is ____________________.

Question 47

Putting a semicolon after the parentheses following the expression in an if statement (that is,before the statement)is a(n)____________________ error.

Question 48

Once an input stream enters a(n)____________________ state,all subsequent input statements associated with that input stream are ignored,and the computer continues to execute the program,which produces erroneous results.

Question 49

To output results correctly,the switch structure must include a(n)____________________ statement after each cout statement,except the last cout statement.

Question 50

The term ____________________ describes a process in which the computer evaluates a logical expression from left to right and stops as soon as the value of the expression is known.