Deck 5: Control Structures II: Repetition

Question 1

A loop is a control structure that causes certain statements to be executed over and over until certain conditions are met.

Answer 1

True

Question 2

If the while expression becomes false in the middle of the while loop body, the loop terminates immediately.

Answer 2

False

Question 3

The output of the Java code, assuming that all variables are properly declared, is 32.num = 10;
while (num<= 32);
num = num + 5;
System.out.println(num);

Answer 3

False

Question 4

A while loop is a post-test loop.

Question 5

Control variables are automatically initialized in a loop.

Question 6

Assume that all variables in the following code are properly declared and that the input is 3 7 4 -1. The output is 13.
num = console.nextInt();
sum = num;
while (num != -1)
{
num = console.nextInt();
sum = sum + num;
}System.out.println(sum);

Question 7

In the for statement, if the logical expression is omitted, it is assumed to be false.

Question 8

To read data from a file of unspecified length, an EOF-controlled while loop is a better choice than a counter-controlled while loop.

Question 9

The following for loop executes 21 times. (Assume all variables are properly declared.)for (i = 1; i <= 20; i = i + 1): System.out.println(i);

Question 10

Like a do...while loop, the body of a while loop executes at least once.

Question 11

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

Question 12

In the case of an infinite while loop, the while expression (that is, the loop condition) is always true.

Question 13

The output of the following Java code is: Stoor.int count = 5;
System.out.print("Sto");do
{
System.out.print('o');
count--;
}
while (count >= 5);System.out.println('r');

Question 14

The control statements in the for loop include the initial expression, logical expression, and update expression.

Question 15

A counter-controlled loop is used when the exact number of data entries is known.

Question 16

The loop condition of a while loop is reevaluated before every iteration of the loop.

Question 17

EOF-controlled while loop is another name for sentinel-controlled while loop.

Question 18

A loop that continues to execute endlessly is called an endless loop.

Question 19

The output of the Java code, assuming that all variables are properly declared, is: 2 3 4 5 6.n = 2;
while (n >= 6)
{
System.out.print(n + " ");
n++;
}
System.out.println();

Question 20

A syntax error will result if the control statements of a for loop are omitted.

Question 21

boolean found = false;
Int num;
Int square;while (!found)
{
Num = console.nextInt();
Square = num * num;
If (square > 40)
Found = true;
}The above code is an example of a(n) ____ loop.

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

Question 22

static final int EndVal = -1;
Int double;
Int num = console.nextInt();while (num != EndVal)
{
Double = num * 2;
System.out.println(double);
Num = console.nextInt();
}The above code is an example of a(n) ____ while loop.

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

Question 23

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

A) 21
B) 34
C) 55
D) 89

Question 24

Which of the following is NOT a reserved word in Java?

A) do
B) while
C) for
D) loop

Question 25

Which of the following is true about a while loop?

A) The body of the loop is executed at least once.
B) The logical expression controlling the loop is evaluated before the loop is entered and after the loop exists.
C) The body of the loop may not execute at all.
D) It is a post-test loop

Question 26

Because a do...while loop is a post-test loop, the body of the loop may not execute at all.

Question 27

If a continue statement is placed in a do...while structure, the loop-continue test is evaluated immediately after the continue statement.

Question 28

int sum = 0;int limit = console.nextInt();
Int counter = 0;while (counter <= limit){
Entry = console.nextInt();
Sum = sum + entry;
Counter++;
}The above code is an example of a(n) ____ while loop.

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

Question 29

int i;for (i = 0; i <= 10; i++)
System.out.println("*");
System.out.println("!");Which of the following is the initial expression in the for loop above?

A) i = 0;
B) i
C) i++
D) System.out.println("*");

Question 30

int i;for (i = 0; i <= 10; i++)
System.out.println("*");
System.out.println("!");Which of the following is the update expression in the for loop above?

A) i = 0;
B) i
C) i++
D) System.out.println("*");

Question 31

After a break statement executes, the program continues to execute with the first statement after the structure.

Question 32

What is the output of the following Java code?int num = 15;
While (num > 0)
Num = num - 3;
System.out.println(num);

A) 0
B) 3
C) 12
D) 15

Question 33

The do...while loop has an exit condition but no entry condition.

Question 34

A break statement is legal in a while loop, but not in a for loop.

Question 35

Suppose sum and num are int variables, and the input is
20 25 10 18 -1 What is the output of the following code? (Assume that console is a Scanner object initialized to the standard input device.)sum = 0;
Num = console.nextInt();
While (num != -1)
{
If (num >= 20)
Sum = sum + num;
Else
Sum = sum - num;
Num = console.nextInt();
}
System.out.println(sum);

A) 17
B) 28
C) 45
D) 60

Question 36

ch = inFile.next().charAt();while (inFile.hasNext())
{
System.out.println(ch);
Ch = inFile.next().charAt();
}The above code is an example of a(n) ____ loop.

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

Question 37

What is the value of counter after the following statements execute?counter = 1;
While (counter<30)
Counter = 2 * counter;

A) 16
B) 32
C) 64
D) 53

Question 38

int i;for (i = 0; i <= 10; i++)
System.out.println("*");
System.out.println("!");Which of the following is the logical expression in the for loop above?

A) i = 0;
B) i
C) i++
D) System.out.println("*");

Question 39

What is value of x after the following code executes?int x = 0;
Int i;for (i = 0; i < 5; i++)
X = 3 * x + i;

A) 18
B) 58
C) 179
D) 226

Question 40

What is the output of the following code?int count;
Int num = 2;for (count = 1; count " ");
}
System.out.println();

A) 5
B) 5 8
C) 2 5 8
D) 5 8 11

Question 41

int x = 27;
Int y = 10;do
X = x / 3;
While (x >= y);What is the final value of x in the code above?

A) 0
B) 3
C) 9
D) 27

Question 42

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

A) statement
B) logical expression
C) initial statement
D) update expression

Question 43

Which of the following is true about a do...while loop?

A) The body of the loop is executed at least once.
B) The logical expression controlling the loop is evaluated before the loop is entered.
C) The body of the loop may not execute at all.
D) It is a pretest loop.

Question 44

Which of the following is not a function of the break statement?

A) To exit early from a loop
B) To skip the remainder of a switch structure
C) To eliminate the use of certain boolean variables in a loop
D) To ignore certain values for variables and continue with the next iteration of a loop

Question 45

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 46

int x = 27;
Int y = 10;do
X = x / 3;
While (x >= y);How many times does the statement above execute?

A) none
B) once
C) twice
D) three times

Question 47

Which executes immediately after a continue statement in a for loop?

A) initial statement
B) update statement
C) loop condition
D) the body of the loop

Question 48

Which of the following does not have an entry condition?

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

Question 49

Where is the continue statement NOT usually used?

A) while loops
B) for loops
C) switch structures
D) do...while loops

Question 50

int x = 27;
Int y = 10;do
X = x / 3;
While (x >= y);If y = 0, how many times would the loop above execute?

A) 1
B) 2
C) 3
D) 4