NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
MARCH/APRIL 2016 EXAMINATION

COURSE CODE:                                                                              CIT383

COURSE TITLE:                                                                             Introduction to Object-Oriented Programming

TIME ALLOWED:                                                                          2½ Hours

INSTRUCTIONS:                                                                            Answer any Four (4) Questions

1a.       Give the full meaning of the following acronyms:

(i)        WYSIWYG                  (ii)       OSI                  (iii)      PCS                  (iv)      RDO

(v)       ADT                            (vi)      OOD                (vii)     API                  (viii)    URL

(ix)      GUI                                                                                                                          1 mark each

1b.       Differentiate between an instance variable and a static field?                                             4 marks

1c.       List three main features of Object Oriented Programming?                                           4 ½ marks

2a.       What is the value of x after each of the following statement is executed:

(i)        x=Math.abs(-7.5);                  (ii)       x=Math.floor(-3.7);

(iii)      x=Math.ceil(6.3);                   (iv)      x=Math.floor(4.1);

(v)       x=Math.ceil(-2.5);                  (vi)      x=Math.pow(2,8);

(vii)     x=Math.ceil(-Math.abs(-5+Math.floor(-3.2)));                                            1 ½ marks each

2b.       List three popular Object Oriented Languages?                                                                     3 marks

2c.       Mention two advantages of software reusability                                                                 4 marks

3a.       Write short note on the following:

1. Inheritance
2. Encapsulation                                                                                                      3 marks each

3b.       Explain the term “methods”                                                                                                    7 marks

3c.       List three (3) examples of methods                                                                                                4½ marks

4a.       What do you understand by Operator Overloading?                                                          7 marks

4b.       List and explain three key restrictions to overloading the conversion operators           6 marks

4c.       List the three (3) logical operators that can directly overloaded for s class                 4½ marks

5a        What is the difference between a Class and an Object?                                                      8 marks

5b.       Explain the term “downcasting”                                                                                             5 marks

5c.       Enumerate, giving examples any three (3) examples of Message Passing styles          4 ½ marks

6a.       Write a short note on each of the following:

1. Overloaded and Overridden Method
2. Local Variables and Instance Variables
3. Set and Get Methods                                                                                           3 marks each

6b.       Explain the term “Object Oriented Programming Language”                                             4 marks

6c.       List three main features of Object Oriented Programming?                                           4 ½ marks