Deck 5: Control Structures II Repetition

Question 1

Suppose sum and num are int variables, and the input is 18 25 61 6 -1. What is the output of the following code? sum = 0;
Cin >> num;
While (num != -1)
{
Sum = sum + num;
Cin >> num;
}
Cout << sum << endl;

A) 92
B) 109
C) 110
D) 119

Answer 1

C

Question 2

A(n) ____-controlled while loop uses a bool variable to control the loop.

A) counter
B) sentinel
C) flag
D) EOF

Answer 2

C

Question 3

In a sentinel-controlled while loop, the body of the loop continues to execute until the EOF symbol is read.

Answer 3

False

Question 4

The control statements in the for loop include the initial statement, loop condition, and update statement.

Question 5

What is the output of the following C++ code? count = 1;
Num = 25;
While (count < 25)
{
Num = num - 1;
Count++;
}
Cout << count << " " << num << endl;

A) 24 0
B) 24 1
C) 25 0
D) 25 1

Question 6

Consider the following code. (Assume that all variables are properly declared.) cin >> ch;
While (cin)
{
Cout << ch;
Cin >> ch;
}
This code is an example of a(n) ____ while loop.

A) sentinel-controlled
B) flag-controlled
C) EOF-controlled
D) counter-controlled

Question 7

Assume that all variables are properly declared. The following for loop executes 20 times.
for (i = 0; i <= 20; i++)
cout << i;

Question 8

The number of iterations of a counter-controlled loop is known in advance.

Question 9

In the case of the sentinel-controlled while loop, the first item is read before the while loop is entered.

Question 10

Assume all variables are properly declared. The output of the following C++ code is 2 3 4 5.
n = 1;
while (n < 5)
{
n++;
cout << n << " ";
}

Question 11

The statement in the body of a while loop acts as a decision maker.

Question 12

Which of the following statements generates a random number between 0 and 50?

A) srand(time(0));
Num = rand() % 50;
B) srand(time(10));
Num = rand()/50;
C) srand(time(0));
Num = rand()50;
D) srand(time(10));
Num = rand() % 50;

Question 13

In a counter-controlled while loop, the loop control variable must be initialized before the loop.

Question 14

What is the output of the following C++ code? num = 10;
While (num > 10)
Num = num - 2;
Cout << num << endl;

A) 0
B) 6
C) 8
D) 10

Question 15

In ____ structures, the computer repeats particular statements a certain number of times depending on some condition(s).

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

Question 16

Consider the following code. int limit;
Int reps = 0;
Cin >> limit;
While (reps < limit)
{
Cin >> entry;
Triple = entry * 3;
Cout << triple;
Reps++;
}
Cout << endl;
This code is an example of a(n) ____ while loop.

A) flag-controlled
B) counter-controlled
C) EOF-controlled
D) sentinel-controlled

Question 17

What is the output of the following C++ code? num = 100;
While (num <= 150)
Num = num + 5;
Cout << num << endl;

A) 150
B) 155
C) 160
D) 165

Question 18

A loop that continues to execute endlessly is called a(n) ____ loop.

A) end
B) unhinged
C) infinite
D) definite

Question 19

The following while loop terminates when j > 20.
j = 0;
while (j < 20)
j++;

Question 20

The control variable in a flag-controlled while loop is a bool variable.

Question 21

What is the output of the following loop? count = 5;
Cout << 'St';
Do
{
Cout << 'o';
Count--;
}
While (count <= 5);

A) St
B) Sto
C) Stop
D) This is an infinite loop.

Question 22

Which of the following loops does not have an entry condition?

A) EOF-controlled while loop
B) sentinel-controlled while loop
C) do...while loop
D) for loop

Question 23

____ loops are called posttest loops.

A) break
B) for
C) while
D) do...while

Question 24

Which executes first in a do...while loop?

A) the statement
B) loop condition
C) the expression
D) update statement

Question 25

A semicolon at the end of the for statement (just before the body of the loop) is a(n) ____________________ error.

Question 26

Which of the following is a repetition structure in C++?

A) if
B) switch
C) while...do
D) do...while

Question 27

A for loop is typically called a counted or ____________________ for loop.

Question 28

Suppose sum, num, and j are int variables, and the input is 4 7 12 9 -1. What is the output of the following code? cin >> sum;
Cin >> num;
For (j = 1; j <= 3; j++)
{
Cin >> num;
Sum = sum + num;
}
Cout << sum << endl;

A) 24
B) 25
C) 41
D) 42

Question 29

Which of the following loops is guaranteed to execute at least once?

A) counter-controlled while loop
B) for loop
C) do...while loop
D) sentinel-controlled while loop

Question 30

What executes immediately after a continue statement in a while and do-while loop?

A) loop-continue test
B) update statement
C) loop condition
D) the body of the loop

Question 31

The function srand takes as input a(n) ____________________ int, which acts as the seed for the algorithm.

Question 32

The ____ statement can be used to eliminate the use of certain (flag) variables.

A) while
B) switch
C) break
D) if

Question 33

What is the value of x after the following statements execute? int x = 5;
Int y = 30;
Do
X = x * 2;
While (x < y);

A) 5
B) 10
C) 20
D) 40

Question 34

What is the initial statement in the following for loop? (Assume that all variables are properly declared.) int i;
For (i = 1; i < 20; i++)
Cout << "Hello World";
Cout << "!" << endl;

A) i = 1;
B) i < 20;
C) i++;
D) cout << "Hello World";

Question 35

The function eof is a member of the data type ____________________.

Question 36

Suppose j, sum, and num are int variables, and the input is 26 34 61 4 -1. What is the output of the code? sum = 0;
Cin >> num;
For (int j = 1; j <= 4; j++)
{
Sum = sum + num;
Cin >> num;
}
Cout << sum << endl;

A) 124
B) 125
C) 126
D) 127

Question 37

What is the output of the following C++ code? int j;
For (j = 10; j <= 10; j++)
Cout << j << " ";
Cout << j << endl;

A) 10
B) 10 10
C) 10 11
D) 11 11

Question 38

To generate a random number, you can use the function rand of the header file ____________________.

Question 39

What is the next Fibonacci number in the following sequence? 1, 1, 2, 3, 5, 8, 13, 21, ...

A) 34
B) 43
C) 56
D) 273

Question 40

When a continue statement is executed in a ____, the update statement always executes.

A) while loop
B) for loop
C) switch structure
D) do...while loop

Question 41

A do...while loop is a(n) ____________________ loop, since the loop condition is evaluated after executing the body of the loop.

Question 42

The for loop body executes indefinitely if the loop condition is always ____________________.

Question 43

In a while and for loop, the loop condition is evaluated before executing the body of the loop. Therefore, while and for loops are called ____________________ loops.

Question 44

The ____________________ statement is typically used for two purposes:
• To exit early from a loop.
• To skip the remainder of a switch structure.

Question 45

Putting one control structure statement inside another is called ____________________.

Question 46

In a(n) "____________________" problem, either the loop executes one too many or one too few times.

Question 47

A software ____________________ is a piece of code written on top of an existing piece of code intended to fix a bug in the original code.

Question 48

A loop ____________________ is a set of statements that remains true each time the loop body is executed.

Question 49

The ____________________ loop has an exit condition but no entry condition.

Question 50

If a(n) ____________________ statement is placed in a do...while structure, the loop-continue test is evaluated immediately after this statement.