Deck 6: Looping

Question 1

An indefinite loop is a(n) ____ loop.

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

Answer 1

B

Question 2

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

Answer 2

False

Question 3

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

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

Answer 3

A

Question 4

Which is an infinite loop?

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

Question 5

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

Question 6

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

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

Question 7

____ 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 8

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

Question 9

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

Question 10

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

Question 11

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

Question 12

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

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

Question 13

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

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

Question 14

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 15

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

Question 16

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

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

Question 17

Programmers rarely use indefinite loops when validating input data.

Question 18

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 19

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

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

Question 20

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

Question 21

How many times will outputLabel be called? for(customer = 1; customer
     for(color = 1; color
          outputLabel();

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

Question 22

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 23

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

Question 24

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 25

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

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

Question 26

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

Question 27

The ____________________ loop is the posttest loop used in Java.

Question 28

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

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

Question 29

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

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

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

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 32

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 33

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

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

Question 34

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

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

Question 35

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

Question 36

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 37

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 38

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 39

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 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 42

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". Get user input of another value for userNum after each println statement. Once MAXVALUE is reached, create a final println statement that will output "Max value reached".

Question 43

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

Question 44

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

Question 45

How does a for loop work?

Question 46

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 47

counterLoop = 1;
while(counterLoop
{
     System.out.println("Hello");
     counterLoop = counterLoop + 1;
}
What is the problem in the above while loop? How would you correct the problem?

Question 48

Describe how a loop is controlled by a Boolean expression.

Question 49

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

Question 50

Provide a code example of a pretest loop and an example of a posttest loop.

Question 51

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

Question 52

What is loop fusion? Write a code segment that uses loop fusion to call two methods, method1 and method2 , 10 times each.

Question 53

Using the flowchart and code above, describe the execution of the loop. Identify the loop control variable and the value of the variable as the code is executed.

Question 54

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

Question 55

What are some unconventional uses of the three sections inside the parentheses of a  for loop? Show at least three examples using code.

Question 56

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

Question 57

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 58

What are the three sections inside the parentheses of a for loop typically used for?

Question 59

Explain why an infinite loop might not actually execute infinitely.

Question 60

How are nested loops implemented in a loop structure?

Question 61

while(count
Examine the statement above. Write the code that will result in more efficient program execution assuming the result of getNumberOfEmployees() stays the same.

Question 62

while(10 > 1)
{
   System.out.println("This prints forever.");
}
Identify the problem that exists in the above while loop.

Question 63

public class IncrDemo
{
    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 64

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 65

Using the information provided above, write the while loop that will correctly follow the execution of the flowchart.

Question 66

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.