Question 5

0 / 1 point

When designing a class, what is one of the first tasks that need to be done?

Question options:

	Defining the instance variables
	Writing the method headers
	Specifying the public interface
	Adding comments to your program
Question 6		0 / 1 point

Consider the following code segment:

class Fruit : 

 _type = "Fruit" 

 def __init__(self, color) : 

 self._color = color 

What is the name of the class variable?

Question options:

	color
	_color
	self
	_type
Question 7		0 / 1 point

Where is an object's data stored?

Question options:

	Global variables
	Instance variables
	Local variables
	Parameter variables
Question 10		0 / 1 point

Which of the following is NOT a pattern used to help design the data representation of a class?

Question options:

	An instance variable for thte total is updated in methods that increase or decrease the total amount
	An object reference specifies the location of an object
	An object can collect other objects in a list
	To model a moving object, you need to store and update its position
Question 12		0 / 1 point

What method name is used for a constructor?

Question options:

	__begin__
	__construct__
	__create__
	__init__
Question 13		0 / 1 point

Which name would be best for a private instance variable?

Question options:

	_confidential
	HIDDEN
	private
	Secret
Question 18		0 / 1 point

How do you access instance variables in a method?

Question options:

	Using the constructor
	Using the public interface
	Using a default value
	Using the self reference
Question 19		0 / 1 point

Which of the following patterns can be used for designing your class for a train object that drives along a track and keeps track of the distance from the terminus?

Question options:

	Describing the Position of an Object
	Modeling Objects with Distinct States
	Managing Properties of an Object
	Collecting Values

Consider the following class:

class Counter : 

 def getValue(self) : 

 return self._value 

 def click(self) : 

 self._value = self._value + 1 

 def unClick(self) : 

 self._value = self._value - 1 

 def reset(self) : 

 self._value = 0 

Which method creates a new instance variable?

Question options:

	click
	getValue
	reset
	unClick
Question 7		0 / 1 point

Consider the following class:

class Fruit : # Line 1 

 def getColor(self) : # Line 2 

 retval = self._color # Line 3 

 return retval # Line 4 

Which line(s) are part of the public interface for the class?

Question options:

	Only line 1
	Only line 2
	Only lines 2 and 3
	Only lines 3 and 4
Question 9		0 / 1 point

Consider the following class:

class Counter : 

 def getValue(self) : 

 return self._value 

 def click(self) : 

 self._value = self._value + 1 

 def unClick(self) : 

 self._value = self._value - 1 

 def reset(self) : 

 self._value = 0 

Which method is an accessor?

Question options:

	getValue
	click
	unClick
	reset
Question 11		0 / 1 point

Consider the following class:

class Counter : 

 def getValue(self) : 

 return self._value 

 def click(self) : 

 self._value = self._value + 1 

 def unClick(self) : 

 self._value = self._value - 1 

 def reset(self) : 

 self._value = 0 

Which method(s) are mutators?

Question options:

	Only reset
	Only click and unClick
	Only click, unClick and reset
	All four methods are mutators
Question 14		0 / 1 point

Consider the following class:

class Contact : 

 def __init__(self, name, phone="") 

 self._name = name 

 self._phone = phone 

 def getName(self) : 

 return self._name 

 def setName(self, new_name) : 

 self._name = new_name 

 def getPhone(self) : 

 return self._phone 

 def setPhone(self, new_phone) : 

 self._phone = new_phone 

What is output by the following code segment?

p1 = Contact("Bob", "555-123-4567") 

p2 = Contact("Joe", "555-000-0000") 

p1.setName(p2.getName()) 

print(p1.getPhone()) 

Question options:

	Bob
	Joe
	555-000-0000
	555-123-4567
Question 16		0 / 1 point

Which method below would be considered an accessor method?

Question options:

	getCount()
	addItem()
	clearCount()
	updateItem()
Question 17		0 / 1 point

Which statement determines if the middleInit variable is empty or does not refer to any object?

Question options:

	if middleInit is None : print("No middle initial")
	if middleInit is not None : print("No middle initial")
	if middleInit == None : print("No middle initial")
	if middleInit != None : print("No middle initial")
Question 18		0 / 1 point

Which of the following statements determines if x currently refers to an object containing an integer?

Question options:

	if int(x) :
	if x == int :
	if x is int :
	if isinstance(x, int) :

Suppose you have a class ShoppingList, with instance variables _quantity, _cost, and _itemName. How should you access these variables when writing code that is not contained within the ShoppingList class?

Question options:

	Directly access the instance variables by using the object and the instance variables' names.
	Use methods provided by the ShoppingList class.
	It is not possible to access the instance variables outside of the ShoppingList class.
	Use the self parameter followed by the instance variables' names.
Question 7		0 / 1 point

What is the purpose of the self parameter?

Question options:

	Enables changes in the implementation without affecting users of a class
	To create variables with public visibility
	Store the data for all objects created by the same class
	Refers to the object on which the method was invoked
Question 11		0 / 1 point

When using the process of tracing objects for problem solving, which types of methods update the values of the instance variables?

Question options:

	Accessor methods
	Mutator methods
	Constructors
	Both B and C
Question 12		0 / 1 point

Before invoking a method on an object, what must be done first?

Question options:

	Initialize all instance variables
	Invoke the accessor and mutator methods
	Create a public interface
	Construct the object
Question 14		0 / 1 point

Which of the following method headers represent a constructor for an Employee class?

Question options:

	def Employee(self) :
	def __init()__ :
	def __Employee__(self) :
	def __init__(self) :
Question 15		0 / 1 point

Which of the following statements is not legal?

Question options:

	["Hello", "World"].lower()
	"Hello, World".lower()
	["Hello", "World"].pop()
	["Hello, World"].pop()
Question 16		0 / 1 point

Consider the following class:

class Pet: 

 def __init__(self, name): 

 self._name = name 

 def getName(self): 

 ____________________ 

What line of code should be placed in the blank to complete the getName accessor method that is supposed to return the pet's name?

Question options:

	return
	return _name
	return self
	return self._name
Question 19		0 / 1 point

In the following example, which data is considered instance data?

You are assigned the task of writing a program that calculates payroll for a small company. To get started the program should do the following:

Add new employees including their first and last name and hourly wage

Ask for the number of hours worked

Calculate payroll (applying 1.5 for any hours greater than 40)

Print a report of all employees' salary for the week, total of all hours and total of all salaries

Question options:

	firstName, lastName, hoursWorked, hourlyWage
	firstName, lastName, hoursWorked, hourlyWage, payrollAmount
	firstName, lastName, hoursWorked, hourlyWage, totalHours, totalSalary
	firstName, lastName, hoursWorked, hourlyWage, payrollAmount, totalHours, totalSalary
Question 20		0 / 1 point

Which method below would be considered a mutator method?

Question options:

	getCount()
	addItem()
	getTotal()
	printItem()

A subclass object can always be used when a superclass object is expected. This fact is referred to as:

Question options:

	generalized interoperability
	method overriding
	the replacement policy
	the substitution principle
Question 4		0 / 1 point

Assume that a Programmer class inherits from an Employee class, and that both classes have an implementation of an increaseSalary method with the same set of parameters. Which class's increaseSalary method is to be executed is determined by:

Question options:

	checking whether or not the super function is called in the method body.
	the number of instance variables in the class.
	the order in which the programmer declared the classes.
	the type of the object on which the method is invoked.
Question 6		0 / 1 point

Which method is being overridden in the following code segment?

class Car : 

 def __init__(self, make, model, color) : 

 . . . 

 def getMake(self) : 

 . . . 

 def getModel(self) : 

 . . . 

 def getColor(self) : 

 . . . 

class Apple : 

 def __init__(self, color) : 

 . . . 

 def getColor(self) : 

 . . . 

Question options:

	getMake
	getModel
	getColor
	No method is being overridden in this code segment
Question 7		0 / 1 point

Consider the following code snippet:

anEmployee = new Programmer() 

anEmployee.increaseSalary(2500) 

If the Programmer class inherits from the Employee class, and both classes have an implementation of the increaseSalary method with the same set of parameters, which statement is correct?

Question options:

	An additional line of code must be added to the snippet shown previously to specify which method will execute.
	It is not possible to determine which class's method will be executed without seeing the complete class definitions.
	The increaseSalary method of the Employee class will be executed.
	The increaseSalary method of the Programmer class will be executed.
Question 8		0 / 1 point

You are creating a class inheritance hierarchy about motor vehicles that will contain classes named Vehicle, Auto, and Motorcycle. Which of the following statements is correct?

Question options:

	Vehicle should be the subclass, while Auto, and Motorcycle should be the default classes
	Vehicle should be the subclass, while Auto, and Motorcycle should be the superclasses
	Vehicle should be the default class, while Auto, and Motorcycle should be the subclasses
	Vehicle should be the superclass, while Auto, and Motorcycle should be the subclasses
Question 10		0 / 1 point

What is the purpose of using an inheritance hierarchy?

Question options:

	To share common code among the classes
	To create objects from concrete classes
	To create objects from abstract classes
	To create objects using constructors

Attempt Score:

Assuming the Rectangle class is already designed with a constructor __init__(self, x, y, width, height), which code snippet creates a square in the middle of a frame with FRAME_WIDTH = 400, FRAME_HEIGHT = 600?

Question options:

	square = Rectangle(FRAME_WIDTH/2, FRAME_HEIGHT/2, 100, 100)
	square = Rectangle(FRAME_WIDTH, FRAME_HEIGHT, 100, 100)
	square = Rectangle(FRAME_WIDTH-50, FRAME_HEIGHT - 50, 100, 100)
	square = Rectangle(FRAME_WIDTH/2 - 50, FRAME_HEIGHT/2 - 50, 100, 100)
Question 7		0 / 1 point

Consider the following class hierarchy:

class Vehicle : 

 def __init__(self, type) : 

 self._type = type 

class LandVehicle(Vehicle) : 

 def __init__(self, type) : 

 super().__init__(type) 

class Auto(Vehicle) : 

 def __init__(self, type) : 

 ____________________________ 

Complete the code in the Auto class constructor to store the type data.

Question options:

	super(type)
	super().super().__init__(type)
	super().__init__(type)
	This cannot be done unless the Auto class declares an instance variable named type.
Question 8		0 / 1 point

Which of the following statements indicates that ClassA is a superclass of ClassB?

Question options:

	class ClassB(ClassA) :
	class ClassA(ClassB) :
	class ClassB extends ClassA :
	class ClassA extends ClassB :
Question 10		0 / 1 point

Which of the following statements is true?

Question options:

	A method that is overridden in a subclass can perform a task that is totally different from the task performed by the same method in the superclass.
	A method that is overridden in a subclass cannot invoke the method in the superclass with the same name.
	A method that is overridden in a subclass must extend the functionality of the superclass by invoking the superclass method.
	Every method in a subclass must override a superclass method.

If a class has an abstract method, which of the following statements is NOT true?

Question options:

	You cannot inherit from this class.
	You cannot construct an object from this class.
	You can construct an object from this class.
	All non-abstract subclasses of this class must implement this method.
Question 6		0 / 1 point

Which of the following statements about abstract methods is true?

Question options:

	An abstract method has a name and parameters, but its implementation is not specified.
	An abstract method has parameters and is fully implemented, but it has no defined name.
	An abstract method has a name and is fully implemented, but it has no parameters.
	An abstract method has only a name, but it implementation is not specified and it has no parameters.
Question 9		0 / 1 point

Which of the following is true regarding subclasses?

Question options:

	A subclass that inherits methods from its superclass may not override the methods.
	A subclass that inherits instance variables from its superclass may not declare additional instance variables.
	A subclass may inherit methods or instance variables from its superclass but not both.
	A subclass may inherit methods and instance variables from its superclass, and may also implement its own methods and declare its own instance variables.

Complete the code for the myFactorial recursive function shown below, which is intended to compute the factorial of the value passed to the function:

1. def myFactorial(n) : 

2. if n == 1 : 

3. return 1 

4. else : 

5. _______________________ 

Question options:

	return n * myFactorial(n)
	return (n - 1) * myFactorial(n)
	return n * myFactorial(n - 1)
	return (n - 1) * myFactorial(n - 1)
Question 2		0 / 1 point

Consider the following recursive code snippet:

1. def mystery(n, m) : 

2. if n == 0 : 

3. return 0 

4. if n == 1 

5. return m 

6. return m + mystery(n - 1, m) 

What value is returned from a call to mystery(3,6)

Question options:

	3
	6
	18
	729
Question 3		0 / 1 point

A palindrome is a word or phrase that reads the same forward and backward. Consider the functions palindrome and isPal shown below:

def palindrome(s) : 

 return isPal(s, 0, len(s) - 1) 

def isPal(s, left, right) : 

 if left >= right : 

 return True 

 elif s[left] == s[right] : 

 return isPal(s, left + 1, right - 1) 

 else : 

 return False 

The function isPal as shown here would be considered to be a ____ function.

Question options:

	iterative
	method
	helper
	static
Question 4		0 / 1 point

Consider the following recursive function:

def myPrint(n) : 

 if n < 10 : 

 print(n) 

 else : 

 m = n % 10 

 print(m, end="") 

 myPrint(n // 10) 

What is printed for the call myPrint(821)?

Question options:

	10
	12
	128
	821
Question 6		0 / 1 point

Which of the following options could be used as a terminating condition for a recursive function that finds the middle character of a String with any number of characters?

I. the length of the String is 1

II. first and last String characters match

III. the String is not empty

Question options:

	I
	II
	I, II, and III
	I and III
Question 7		0 / 1 point

Why does the best recursive function usually run slightly slower than its iterative counterpart?

Question options:

	Testing the terminating condition takes longer.
	Each recursive function call takes processor time.
	Multiple recursive cases must be considered.
	Checking multiple terminating conditions take more processor time.
Question 8		0 / 1 point

A palindrome is a word or phrase spelled which reads the same forward or backward. Consider the following code snippet:

def palindrome(s) : 

 return isPal(s, 0, len(s) - 1) 

def isPal(s, left, right) : 

 if left >= right : 

 return True 

 elif s[left] == s[right] : 

 return isPal(s, left + 1, right - 1) 

 else : 

 return False 

What does the function palindrome return?

Question options:

	True
	False
	a palindrome not found exception
	the Boolean value returned from the isPalfunction
Question 9		0 / 1 point

Consider the following function:

1. def mystery(n, m) : 

2. if n == 0 : # special case 1 

3. return 0 

4. if n == 1 : # special case 2 

5. return m 

6. return m + mystery(n - 1), m) 

What will happen if lines #2 and #3 were swapped with lines #4 and #5?

Question options:

	The original function and the modified function will return the same result for all integer values of n and m.
	The original function and the modified function will return different results for all integer value of n and m.
	The original function and the modified function will return the same result when n is greater than m, and different results when m is greater than n.
	The original function and the modified function will return the same result when n is less than m, and different results when m is less than n.
Question 10		0 / 1 point

Recursion will take place if any of the following happen:

I. function A calls function B, which calls function C

II. function A calls function B, which calls function A

III. function A calls function A

Question options:

	I
	I and II
	II
	II and III

6 / 10 - D

8 / 10 - B

The following function is supposed to use recursion to compute the area of a square from the length of its sides. For example, squareArea(3) should return 9.

def squareArea(sideLength) : 

 if sideLength == 1 : 

 return 1 

 else : 

 ____________________ 

What line of code should be placed in the blank to achieve this goal?

Question options:

	return squareArea(sideLength - 1)
	return 2 * squareArea(sideLength - 1)
	return 2 * sideLength + squareArea(sideLength - 1)
	return 2 * (sideLength - 1) + squareArea(sideLength - 1)
Question 2		0 / 1 point

Which statement finds all of the links in a webpage?

Question options:

	elements = doc.find_all("a")
	elements = doc.find_all("li")
	elements = doc.find_all(links)
	elements = doc.find_links()
Question 3		0 / 1 point

Complete the code for the myFactorial recursive function shown below, which is intended to compute the factorial of the value passed to the function:

1. def myFactorial(n) : 

2. if n == 1 : 

3. _____________________________ 

4. else : 

5. return n * myFactorial(n - 1) 

Question options:

	return 0
	return -n
	return 1
	return myFactorial(n)
Question 4		0 / 1 point

Consider the code for the recursive function myPrint shown in this code snippet:

1. def myPrint(n) : 

2. if n == 0 : 

3. return 0 

4. else : 

5. return n + mysteryPrint(n - 1) 

To avoid infinite recursion, which of the following lines of code should replace the current terminating case?

Question options:

	if n == -1
	if n <= 0
	if n >= 0
	The terminating case as shown will avoid infinite recursion
Question 5		0 / 1 point

Consider the function powerOfTwo shown below:

1. def powerOfTwo(n) : 

2. if n == 1 : 

3. return True 

4. elif n % 2 == 1 : 

5. return False 

6. else : 

7. return powerOfTwo(n / 2) 

How many recursive calls are made from the original call powerOfTwo(64) (not including the original call)?

Question options:

	8
	6
	4
	2
Question 7		0 / 1 point

Consider the following code segment:

def f1(n) : 

 if n < 0 : 

 return 0 

 if n % 2 == 1 : 

 return n 

 return f2(n + 1) 

def f2(n) : 

 if n < 0 : 

 return 0 

 if n % 2 == 0 : 

 return n 

 return f1(n // 2) 

This code segment would be classified as:

Question options:

	backtracking
	mutually recursive
	non-recursive
	object oriented
Question 10		0 / 1 point

Consider the following code segment:

def f1(n) : 

 if n < 0 : 

 return 0 

 if n % 2 == 1 : 

 return n 

 return f2(n + 1) 

def f2(n) : 

 if n < 0 : 

 return 0 

 if n % 2 == 0 : 

 return n 

 return f1(n // 2) 

print(f2(7)) 

When this code is run, it will display:

Question options:

	0
	1
	3
	7
Question 2			0 / 1 point

Which problem is well suited to being solved with mutually recursive functions?

Question options:

	Computing the factorial of a number
	Determining if a string is a palindrome
	Computing Fibonacci numbers
	Evaluating a numeric expression
Question 3		0 / 1 point

A unique permutation is one that is different from any other generated permutation. How many unique permutations does the string "bee" have?

Question options:

	2
	3
	4
	5
Question 4		0 / 1 point

Recall the permutations function from Section 11.5 in the textbook.

def permutations(word) : 

 result = [] 

 if len(word) == 0 : 

 result.append(word) 

 return result 

 else: 

 for i in range(len(word)) : 

 shorter = word[ : i] + word[i + 1 : ] 

 shorterPermutations = permutations(shorter) 

 for string in shorterPermutations : 

 result.append(word[i] + string) 

 return result 

How permutations will be generated by calling permutations("code")?

Question options:

	1
	4
	10
	24
Question 5		0 / 1 point

How many recursive calls to the fib function shown below would be made from an original call to fib(4)? (Do not count the original call)

1. def fib(n) : 

2. # assumes n >= 0 

3. if n <= 1 : 

4. return n 

5. else : 

6. return fib(n - 1) + fib(n - 2) 

Question options:

	1
	2
	4
	8
Question 7		0 / 1 point

Consider the triangleArea function from the textbook shown below:

1. def triangleArea(sideLength) : 

2. if sideLength <= 0 : 

3. return 0 

4. if sideLength == 1 : 

5. return 1 

6. smallerSideLength = sideLength - 1 

7. smallerArea = triangleArea(smallerSideLength) 

8. area = smallerArea + sideLength 

9. return area 

What will happen if line #6 is changed to:

smallerSideLength = sideLength 

Question options:

	Infinite recursion will occur when sideLength is equal to 0.
	Infinite recursion will occur when sideLength is equal to 1.
	Infinite recursion will occur when sideLength is greater than or equal to 2.
	Infinite recursion will occur for any value of sideLength.
Question 10		0 / 1 point

Recall the backtracking strategy outlined in the textbook. A similar strategy can be used to solve Sudoku puzzles.

def solve(gameBoard) : 

 status = examine(gameBoard) 

 if status == CONTINUE : 

 for nextBoard in extend(gameBoard) : 

 solve(nextBoard) 

 elif status == ACCEPT: 

 ____________________ 

What code should be placed in the blank to complete the solution to this problem?

Question options:

	print(status)
	print(gameBoard)
	solve(gameBoard)
	gameBoard = extend(gameBoard)

A particular algorithm visits n³ + nlog(n) + n! elements in order to perform its task on a list of n elements. Which big-Oh expression best describes the growth rate of this algorithm?

Question options:

	O(n)
	O(n3)
	O(n!)
	O(nlog(n))
Question 9		0 / 1 point

Which sort algorithm starts with an initial sequence of size 1, which is assumed to be sorted, and increases the size of the sorted sequence in the list in each iteration?

Question options:

	insertion sort
	selection sort
	merge sort
	quicksort
Question 10		0 / 1 point

Consider the code for mergeSort shown below, which works correctly:

def mergeSort(values) : 

 if len(values) <= 1 : return 

 mid = len(values) // 2 

 first = values[ : mid] 

 second = values[mid : ] 

 mergeSort(first) 

 mergeSort(second) 

 mergeLists(first, second, values) 

What would happen if the line mid = len(values) // 2 was replaced with the line mid = len(values) // 4

Question options:

	Merge sort would continue to work at the same speed as the original version
	Merge sort would continue to work, but it would be slower than the original version
	Merge sort would continue to work, and it would be faster than the original
	The modified version would not sort the list successfully