1. Programming Fundamentals Lecture #2 Overview of Computer Programming
Junaid Hassan
Lecturer CS & IT Department UOS MBDIN

2. Programming/Coding
Set of rules to instruct computers to perform certain tasks is called as programming.
A language which is understandable by computers is called as programming language

3. Purpose of the course
To understand different programming concepts and to familiarize students with the basic structured programming skills.
Problem analysis, algorithm designing, program development and testing/debugging

4. Overview of Computer Programming
Set of instructions/statements we write to command computers to perform actions & make decisions is called a computer program/software
Programming language that we will use (in this course) is C/C++
C++ is the next version or superset of C
C does not support classes & objects because C is a procedural programming language, whereas C++ is a combination of both procedural and object oriented programming capabilities

5. Overview of Computer Programming
A computer is a device that can perform computations & make decisions billions of times faster than humans can.
Computers process data under the control of sets of instructions called computer programs
People who write these computer programs are called as computer programmers

6. Machine Languages, Assembly Languages & High Level Languages
Some programming languages are directly understandable by computers but some languages require intermediate translation steps
There are hundreds of computer languages in use today
These computer programming languages can be divided into three general types:
1) Machine Languages 2) Assembly Languages
3) High Level Languages

7. Machine Languages
A language which is directly understandable by computers is called as machine language. It’s also called as natural language of computers.
Machine languages generally consits of strings of numbers (ultimately reduced to 1’s & 0’s) that instruct computers to perform their most elementary operations one at a time
Machine language programming was too slow, tedious & error prone for most programmers

8. Assembly Languages
Istead of using strings of numbers that computers could directly understand, programmers began using English- Like abbreviations to represent elementary operations
These abbreviations formed the basis of assembly languages
To convert assembly language code to machine language code, translator programs called assemblers were developed

9. Assembly Languages
Although assembly language code is clearer to humans but it’s not understandable by computers until translated to machine language code
In assembly language, programmers still need to use many instructions to accomplish even the simplest tasks
That’s why we moved to next level i.e High level languages

10. High Level Languages
To speed up the programming process, high level languages were developed in which single statements could be written to accomplish substantial tasks
Translator programs used to convert high level language code to machine language code are called compilers.
Advantage of high level language is that we can write instructions like every day English & with commonly used mathematical notations

11. Machine Languages, Assembly Languages, High Level Languages
Requirement: Add overtime pay to base pay & store the result in gross pay
Machine Language Code:

12. Machine Languages, Assembly Languages, High Level Languages
Requirement: Add overtime pay to base pay & store the result in gross pay
Assembly Language Code:
Load basepay
Add overpay
Store grosspay

13. Machine Languages, Assembly Languages, High Level Languages
Requirement: Add overtime pay to base pay & store the result in gross pay
High Level Language Code:
grosspay = basepay + overpay ;

14. Machine Languages, Assembly Languages, High Level Languages
From programmer’s point of view high level languages are preferable to machine & assembly languages
C, C++, Microsoft’s .NET languages (e.g visual basic, visual c++ & visual c#) & java are among the most widely used high level programming languages

15. Real World Application Areas of C/C++
Operating systems
Development of new languages e.g python, php
Computation platforms e.g matlab
Graphics, games, GUI based apps
Web browsers
Database softwares e.g mysql
and many more.....