Object Oriented Programming

BBIT 214:      OBJECT ORIENTED PRORAMMING I

DATE: APRIL 2017                                                                                                   TIME: 2HOURS

Instructions: Attempt QUESTION ONE and ANY OTHER TWO questions

 

Question 1 (30 marks): Compulsory

• Explain the following features of object oriented programing languages. (6marks)
  1. Encapsulation
  2. Inheritance

• Polymorphism

1. Abstraction

• Why is C++ regarded as superset of C language? (2marks)
• Explain the following Object Oriented programming concepts.
  1. Object (2marks)
  2. Message Passing                                                            (2marks)

• Class (2marks)

1. Member function (2marks)

• State four advantages of object oriented languages over the other languages. (4marks)

(i) Define the term variables.                                                                          (2marks)

(ii) Stave four rules for naming variables in C++/ java.                                               (4marks)

(iii) Using example demonstrate how variables are declared and initialized in Java/C++.                                                                                                                                                       (4marks)

 

Question 2 (20marks)

• Define the term array. (2marks)
• Explain three core features of arrays. (6marks)
• Using examples differentiate between one dimensional and two dimensional arrays. Show how each type is declared and initialized in Java/C++.             (8marks)
• Write a program to declare and initialize two integer variables, compare them and print out the larger value on the screen .                                                                       (4marks)

 

Question 3 (20marks)

• Rewrite the program given below using switch case selection control structure construct. (6marks)

 

char letter;

String country;

if(letter ==”A”)

{

country=”Algeria”;

}

else if(letter=”B”)

{

country=”Botswana”;

}

else if(letter=”G”)

{

country=”Gabon”;

}

else

cout<<“Sorry no match for your letter”;

}

 

• Write a program is required to calculate net pay for a casual worker. The user inputs the number of days worked and daily pay using keyboard input. A tax of 16% is deducted from the payable amount. Write a complete program that computes the payable amount, tax deducted and the net pay and display the results. Define functions to compute each of the results.                                                                       (8marks)

 

• Explain the difference between local and global variables as used in C++. Use example code.                                                                                                                                     (6marks)

Question 4 (20marks)

• Define the term constructor. (2marks)
• Write a program to demonstrate how overloaded constructors are declared and used in OO programming.

(6marks)

• Design a class program for a The class consist the following member variables: Student ID, Student Names, Course and Semester fee. The methods include: getStudentDetails (for initializing the student details) and displayStudentDetails (for printing the student details on the screen). The class contains one object Mystudent.

(12marks)

Question 5 (20marks)

(a)    A program is required to compute grades for student performance in OOP. The user inputs the marks scored in the unit to get the grade. The grading system is as follows:

Marks	Grade
0      –  39	Fail
40     – <50	Pass
50     – < 60	Average
60     – < 70	Credit
70   –    100	Distinction
Any other input	Invalid score

 

Using if statement implement the above program.                                                   (8marks)

(b) Give three characteristics of a good user interface.                        .                                   (3marks)

(c) Using examples codes, discuss three types of loops used in programming.                         (9marks)