1. Sayed Ahmed BSc. Engineering in Computer Science and Engineering, BUET, Bangladesh MSc. in Computer Science, University of Manitoba, Canada Owner/Architect/Developer Justetc (Just et cetera) Technologies, Canada http://www.justetc.net http://sayed.justetc.net sayed@justetc.net

2.  Training and Education in Bangla:  http://Bangla.SaLearningSchool.com http://Bangla.SaLearningSchool.com  Training and Education in English:  http://www.SaLearningSchool.com http://www.SaLearningSchool.com  http://English.SaLearningSchool.com http://English.SaLearningSchool.com  Ask questions and get answers  http://Ask.JustEtc.net http://Ask.JustEtc.net  Offline IT Training:  http://University.JustEtc.net http://University.JustEtc.net

3.  Minimize The Accessibility of Classes and Members  Favor Composition Over Inheritance  Program To An Interface, Not An Implementation  The Open-Closed Principle:  Software Entities Should Be Open For Extension, Yet Closed For Modification

4.  The Single Choice Principle:  Whenever a software system must support a set of alternatives, ideally only one class in the system knows the entire set of Alternatives  The Liskov Substitution Principle:  Functions That Use References To Base (Super) Classes Must Be Able To Use Objects Of Derived (Sub) Classes Without Knowing It

5.  I will use the following resource to demonstrate the principles  http://userpages.umbc.edu/~tarr/dp/lectures/ OOPrinciples.pdf http://userpages.umbc.edu/~tarr/dp/lectures/ OOPrinciples.pdf

6.  http://stackoverflow.com/questions/383947/ what-does-it-mean-to-program-to-an-interface http://stackoverflow.com/questions/383947/ what-does-it-mean-to-program-to-an-interface  List myList = new ArrayList(); // programming to the List interface instead of  ArrayList myList = new ArrayList(); // this is bad

7.  Must check  http://www.salearningschool.com/displayArticle.ph p?table=Articles&articleID=819&title=Object%20Or iented%20Analysis:%20Just%20an%20Overview http://www.salearningschool.com/displayArticle.ph p?table=Articles&articleID=819&title=Object%20Or iented%20Analysis:%20Just%20an%20Overview

8.  Trudelle Street, Toronto, Ontario, Canada  Shimultuly, Gazipur, Bangladesh  Justetc Computers  Habib Complex, 2 nd Floor  Contact us  Sayed: sayed@justetc.net (647-624-8509)  Rafik: rafik@justetc.com (01942747702)

9.  I provide consulting under Justetc (Just et cetera) Technologies, Canada  I provide consulting on  Software Development  Web Development  Software Engineering  Software and Information Architecture  Mobile Development  Business Analysis  I have several years of professional experience in different areas of IT, Computer Science, and Software & Computer Engineering  My education and experience exposed me to many abstraction levels of computing; from the lowest level to the highest level (electronics, digital system design, computer networks, data communications, databases, software engineering, software development to web development)