Deck 6: Looping

Question 1

Programmers rarely use indefinite loops when validating input data.

Answer 1

False

Question 2

On many keyboards, the Break key is also the ____ key.

A) Pause
B) Esc
C) Delete
D) Ctrl

Answer 2

A

Question 3

Many seasoned programmers start counter values at 1 because they are used to doing so when working with arrays.

Answer 3

False

Question 4

You can use virtually any number of nested loops; however, at some point, your machine will no longer be able to store all the necessary looping information.

Question 5

Shortcut operators are a programmer's only choice when incrementing or accumulating a variable's value.

Question 6

Making a comparison to 0 is slower than making a comparison to any other value.

Question 7

Altering a variable within both a for statement and within the block it controls can produce errors that are difficult to find.

Question 8

A ____ is a structure that allows repeated execution of a block of statements.

A) body
B) Boolean expression
C) loop
D) loop control

Question 9

____ is the process of ensuring that a value falls within a specified range.

A) Value checking
B) Data integrity
C) Validating data
D) A range check

Question 10

Use a(n) ____ loop to execute a body of statements continually as long as the Boolean expression that controls entry into the loop continues to be true.

A) empty
B) while
C) definite
D) control

Question 11

A loop controlled by the user is a type of ____ loop.

A) indefinite
B) definite
C) counter-controlled
D) incrementing

Question 12

A statement that will alter the value of the loop control variable is included in the body of a loop.

Question 13

Which is an infinite loop?

A) loopCount = 5;
While(loopCount > 3);
{
System.out.println("Hello");
LoopCount = loopCount - 1;
}
B) loopCount = 1;
While(loopCount < 3);
{
System.out.println("Hello");
}
C) loopCount = 4;
While(loopCount < 3);
{
System.out.println("Hello");
LoopCount = loopCount + 1;
}
D) loopCount = 1;
While(loopCount < 3);
{
System.out.println("Hello");
LoopCount = loopCount + 1;
}

Question 14

An indefinite loop is a(n) ____ loop.

A) counter-controlled
B) event-controlled
C) initialized
D) validating

Question 15

In order to improve loop performance, it's important to make sure the loop does not include unnecessary operations or statements.

Question 16

The statements that make up a loop body will continue to execute as long as the expression value remains false.

Question 17

It is important that the loop control ____ be altered within the body of the loop.

A) value
B) variable
C) constant
D) argument

Question 18

A loop that never ends is called a(n) ____ loop.

A) definite
B) infinite
C) while
D) for

Question 19

When nesting loops, the variable in the outer loop changes more frequently.

Question 20

Before entering a loop, the first input, or ____, is retrieved.

A) empty body
B) posttest loop
C) loop body
D) priming read

Question 21

The ____________________ loop is the posttest loop used in Java.

Question 22

The process of repeatedly increasing a value by some amount is known as ____.

A) checking
B) adding
C) accumulating
D) containing

Question 23

A(n) ____ loop is one that performs no actions other than looping.

A) nested
B) do-nothing
C) indefinite
D) posttest

Question 24

The ____ loop checks the value of the loop control variable at the bottom of the loop after one repetition has occurred.

A) while
B) do…while
C) for
D) else

Question 25

In the expressions b = 8 and c = --b, what value will be assigned to the variable c?

A) 8
B) 7
C) 9
D) 10

Question 26

You can initialize more than one variable in a for loop by placing a(n) ____ between the separate statements.

A) semicolon
B) equal sign
C) period
D) comma

Question 27

The order of the conditional expressions in the following is most important within a(n) ____ loop. while(requestedNum > LIMIT || requestedNum < 0)…

A) nested
B) posttest
C) pretest
D) indefinite

Question 28

As long as methods do not depend on one another, ____ is a technique that can improve loop performance by combining two loops into one.

A) loop fusion
B) prefix incrementing
C) short-circuit evaluation
D) do-nothing looping

Question 29

Which of the following is NOT a valid method to increase a variable named score by 1?

A) ++score
B) score++
C) ++score = score + 1
D) score = score + 1

Question 30

In a do…while loop, the loop will continue to execute until ____.

A) the loop control variable is true
B) the loop control variable is false
C) the user types EXIT
D) the program terminates

Question 31

When loops are nested, each pair contains a(n) ____________________ loop and an outer loop.

Question 32

If a(n) ____________________ is altered both within the for statement and within the block it controls, it can be very difficult to follow the program's logic.

Question 33

One execution of any loop is called a(n) ____________________.

Question 34

You use a unary minus sign preceding a value to make the value ____.

A) negative
B) positive
C) valid
D) constant

Question 35

When creating a for loop, which statement will correctly initialize more than one variable?

A) for a=1, b=2
B) for(a=1; b=2)
C) for(a=1, b=2)
D) for(a = 1&& b = 2)

Question 36

When you want to increase a variable's value by exactly 1, use the ____.

A) power statement
B) accumulating operator
C) binary operators
D) prefix increment operator

Question 37

How many times will outputLabel be called? for(customer = 1; customer <= 20; ++customer)
For(color = 1; color <= 3; ++color)
OutputLabel();

A) 0
B) 3
C) 20
D) 60

Question 38

A(n) ____________________ is a body with no statements in it.

Question 39

A for loop provides a convenient way to create a(n) ____ loop.

A) counter-controlled
B) posttest
C) while
D) infinite

Question 40

A(n) ____ loop is a special loop that is used when a definite number of loop iterations is required.

A) while
B) for
C) else
D) do…while

Question 41

Why would a programmer use curly braces in the body of a do…while loop?

Question 42

Why would a loop with altered user input be considered a type of indefinite loop? Give an example.

Question 43

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
A shortcut for incrementing and accumulating

Question 44

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
The value that determines whether loop execution continues

Question 45

Describe the purpose of a loop control variable. How are Boolean values and a while loop involved?

Question 46

Besides initializing, testing, and incrementing, you can also perform other tasks with a for loop. What are some of these tasks? Use code samples as examples.

Question 47

What would happen if a semicolon is mistakenly placed at the end of a partial statement of a while loop with a Boolean expression and with an empty body?

Question 48

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
Subtracting 1 from a variable

Question 49

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
Part of the Thread class in the java.lang package

Question 50

How does a for loop work?

Question 51

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
Within parentheses are three sections separated by exactly two semicolons

Question 52

How are nested loops implemented in a loop structure?

Question 53

How could a programmer identify and escape from an infinite loop?

Question 54

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
Multiple statements within curly braces

Question 55

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
The technique of combining two loops into one

Question 56

How could you rewrite the following code to have the arithmetic performed only once, even if the loop executes 1,000 times?
while (x < a + b)
// loop body

Question 57

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
Operate on two values

Question 58

What are some of the shortcuts Java provides programmers for incrementing and accumulating? Give examples of statements.

Question 59

Describe how a loop is controlled by a Boolean expression.

Question 60

Match each term with the correct statement below.
a.prefix ++
f.loop fusion
b.block
g.decrementing
c.definite loop
h.for loop
d.loop control variable
i.sleep() method
e.binary operators
A counter-controlled loop

Question 61

Explain why an infinite loop might not actually execute infinitely.

Question 62

How are indefinite loops used for validating data? Why is a loop structure typically the better choice for validating data than an if statement?

Question 63

Write a definite while loop that initializes a loop control variable named decreaseOne to 10 and continues until decreaseOne > 0. Decrement the loop control variable by 1 and include the println output "Keep going" within the loop.

Question 64

counterLoop = 1;
while(counterLoop < 10);
{
System.out.println("Enter a new value");
counterLoop = counterLoop + 1;
}
What is the problem in the above while loop? How would you correct the problem?

Question 65

public class CompareValues
{
public static void main(String[] args)
{
int a = 10, b = 10, c = 11;
boolean compare1 = (++b == a);
boolean compare3 = (b++ == c);
System.out.println("Compare 1 value = " + compare1);
System.out.println("Compare 2 value = " + compare2);
}
}
Using the above code, what values will appear in compare1 and compare2 when the println commands execute? Describe how the values of compare1 and compare2 change as the statements are executed.

Question 66

while(10 > 1)
{
System.out.println("Enter a new value");
}
Identify the problem that exists in the above code.

Question 67

public class CaseDemo
{
public static void main(String[] args)
{
int myVal, yourVal;
myVal = 10;
System.out.println("My initial value is " + myVal);
yourVal = ++myVal;
System.out.println("My new value is " + myVal);
System.out.println("Your value is " + yourVal):
}
}
Using the above code, describe how the three println output commands will appear. Explain the values stored in the variables during code execution.

Question 68

Loop control variables can be evaluated at the start or the end of the loop. Describe both pretest loops and posttest loops. How do do…while loops execute?

Question 69

Describe a counter-controlled loop. Explain the process of incrementing and decrementing, and explain the best method for executing a loop a specific number of times.

Question 70

Create an indefinite while loop that will validate that the loop control variable named userNum is less than the constant MAXVALUE. While true, create a println statement to output "Please enter a higher value". Once MAXVALUE is reached, create a final println statement that will output "Max value reached".

Question 71

public class DoWhileExample
{
public static void main(String[] args)
{
int currentValue;
____
____
____
____
____
}
}
Complete the code above by writing a do…while posttest loop that will output the value of the variable currentValue in a println statement. After the output statement, add a decrement statement to decrease the value of currentValue by 1. Continue the loop until currentValue is equal to 0.

Question 72

Write a for loop that will initialize the variables value1 to 11 and value2 to 19. Create a test section of the for statement that will test if value1 is greater than 10 and value2 is less than 20. Finally, end the for statement by incrementing value1 by 1. In the loop body, write a println statement that will display the contents of value1.