Philadelphia University s2

Faculty of Information Technology Philadelphia University Department of Software Engineering Lecturer : Dr. Ali Fouad Examination Paper Coordinator : Dr. Ali Fouad Internal Examiner : Dr. Samer Hanna

Advanced Object Oriented Programming (721324) Sec. 1 Final Exam. First Semester of 2016-2017 Date: 6-2-2017 Time: 120 minutes

Information for Candidates 1. This examination paper contains five questions, totaling 40 marks. 2. The marks for parts of questions are shown in round brackets. Advice to Candidates 1. You should attempt all questions. 2. You should write your answers clearly.

I. Basic concepts Objective: The aim of the question in this part is to evaluate your knowledge and skills concerning with the basic concepts of object oriented.

Question1 (10 marks) 1) What is the difference between = = and is?

 “is” means two variables refer to the same object  “==“ means that two variables or expressions refer to the same value: 2 marks

2) Does the following statements have an error? If so, why? a) t = (1, ‘a’, 9, 2) t[0] = 6

Yes. You cannot change the value of an element in a tuple (what the second line tries to do) because tuples are immutable. 1 mark b) t = [1, ‘a’, 9, 2] t[0] = 6 1 mark

No. You can change the value of an element in a list (what the second line of code is doing) because lists are mutable.

3) Write the output produced by this program below.

1. x = 3 2. if 2 > x : 3. print 'First' 4. else : 5. print 'Second' 6. if 2 > x : 7. print 'Third' 8. print 'Fourth' 9. print `Fifth'

Answer:

Second 1.5 marks Fourth Fifth

4) Write a short Python code segment that adds up the lengths of all the words in a text file and then prints the average (mean) length.

Lword=file(“words.txt”).read().split() sum = 0 for i in lword: 3.5 marks sum = sum + len(i) print float (sum)/len(lword)

5) Write a statement that makes a call to the method “myprint” class MyClass(object): @staticmethod def myprint(x): print x

MyClass. myprint (2) 1 mark

II. Familiar Problem Solving Objective: The aim of the question in this part is to evaluate your ability to solve problems in object oriented programming, focusing on constructors, assessors, and other methods.

Question2 (10 marks) Act like the python interpreter and run the following program. Write what the following would be printed out:

1) colours1 = ["red", "green"] colours2 = colours1 colours2 = ["rouge", "vert"] print colours1  ['red', 'green'] 1 mark colours2 = colours1 colours2[1] = "blue“ print colours1  ['red', 'blue'] 1 mark

2) part = [1,2] whole = [part, part] shallow = whole[:] # not shallow = whole deep = copy.deepcopy(whole) del part[0] print part  [2] 0.5 mark print whole  [[2], [2]] 1 mark print shallow  [[2], [2]] 1 mark print deep  [[1, 2], [1, 2]] 1 mark del deep[0][0] print deep  [[2], [2]] 0.5 mark

def sub(a, b): return a - b list = [(6, 3), (1, 7), (5, 5) , (2, 8)] (2 marks) print [sub(x, y) for (x, y) in list]

[3, -6, 0, -6] each 0.5

4. class Vector: count = 0 def __init__(self,a , b): self.a=a self.b=b count+=1 def __str__(self): return ‘Vector (%d, %d)’% (self.a, self.b)

def __add__(self, other): return Vector(self.a+other.a, self.b+other.b) v1 = Vector(2, 10) v2 = Vector(5, -2) v3 = Vector(1, 1) v4= v1+ v2+ v3 print Vector.count  3 2 marks print v4  Vector (8, 9)

Question3 (15 marks) 1) Write a class named Student has the following data members:

Data member Description name name of the student id identification number of the student scores list of test scores studentGrade student status (pass/no pass)

There will be four member functions: constructor that sets name, id and initializes scores and student grade addscore adds score to list of test scores str to return string representation of the data members get studentGrade returns the student grade

2) Write a derive class UndergraduateStudent form the Student class with method “computeCourseGrade” that sets studentGrade to “pass” if the average of test scores is equal or greater than 60 otherwise sets to “nopass”.

3) Write a derive class PostgraduateStudent form the Student class with method “computeCourseGrade” that sets studentGrade to “pass” if the average of test scores is equal or greater than 70 otherwise sets to “nopass”. class Student(object): def __init__(self, name, id): 2 marks self.name = name self.id = id self.scores = [] self.studentGrade = "“****"

def addscore(self, score): self.scores.append(score) 2 marks def __str__(self): 2 marks return "name:"+ self.name+ "Id:"+self.id+ "studentGrade:"+self.studentGrade

def getstudentGrade(self): 2 mark returns self.studentgrade class UndergraduateStudent(Student): def computeCourseGrade(self): sum=0 for s in self.scores: sum+=s if s/len(self.scores)>=60: 3 marks self.studentGrade="pass" else: self.studentGrade="nopass" class PostgraduateStudent(Student): 2 marks def computeCourseGrade(self): sum=0 for s in self.scores: sum+=s if s/len(self.scores)>=70: self.studentGrade="pass" else: self.studentGrade="nopass"

4) define undergraduate student with name =“Ahmed”, id=”201020018”, scores=[79,90,40], and compute its grade. 2 marks III. Unfamiliar Problem Solving Objective: The aim of the question in this part is to evaluate that student can solve familiar problems with ease and can make progress toward the solution of unfamiliar problems, and can set out reasoning and explanation in clear and coherent manner.

Question4 (5 marks) Create a class named faculty that uses a dictionary to store students with the following methods: constructor method addstudent method to add new student to the faculty removestudent method to remove student from the faculty. reterive method to reterive students informations. totalPass that returns number of the total pass students. class Faculty : def __init__(self): self.d = {}

def addStudent(self, e): self.d[e.id] = e

def removeStudent(self, e): del self.d[e.id]

def reterive(self, id): print self.d[id]

def totalPass (self ): sum=0 for s in d: if s, computeCourseGrade ==”pass”: sum+=1 return sum