1. Introduction to computer programming
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Software Categories
Software is categorized into two main categories
System Software
Application Software
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System Software
The system software controls the computer. It communicates with computer’s hardware (key board, mouse, modem, sound card etc) and controls different aspects of operations.
Sub categories of system software are:
Operating system
Device drivers
Utilities
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Operating System
“Operating system is the software responsible for controlling the allocation and usage of hardware resources such as memory, central processing unit (CPU) time, disk space, and peripheral devices.
The operating system is the foundation on which applications, such as word processing and spreadsheet programs, are built. (Microsoft)” ”
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5. Device drivers/ Utility Software
The device driver software is used to communicate between the devices and the computer.
Utility software is a program that performs a very specific task, usually related to managing system resources.
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Application software
A program or group of programs designed for end users. For example a program for Accounting, Payroll, Inventory Control System, and guided system for planes.
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7. Database Management System
A DBMS is a complex set of software programs that controls the organization, storage, management, and retrieval of data in a database.
It is a set of prewritten programs that are used to store, update and retrieve a Database.
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Computer Viruses
A computer virus is a program which reproduces itself.
It may attach to other programs, it may create copies of itself (as in companion viruses).
It may damage or corrupt data, change data, or degrade the performance of your system by utilizing resources such as memory or disk space.
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Computer Network
A computer network is a group of interconnected computers.
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What is programming
Definition: "A program is a precise sequence of steps to solve a particular problem.”
It means that when we say that we have a program, it actually mean that we know about a complete set activities to be performed in a particular order. The purpose of these activities is to solve a given problem.
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Language?
Way of communication
When we communicate one another then we need a specific language to express our words
Example
English
Urdu
Arabic etc
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Computer Programming
Computer programming is defined as telling a computer what to do through a special set of instructions which are then interpreted by the computer to perform some task(s). These instructions can be specified in one or more programming languages including (but not limited to) Java, PHP, C, and C++.
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Programming Language
A set of words, symbols and codes used to write a programs is called program language.
Different programming languages are available for writing different types of programs.
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14. Types of Computer Programming Language
There are two types of computer programming languages.
Low-Level languages
High- Level Languages
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Low-Level Languages
These are near to computer hardware and far from human language.
Two low-level languages.
Machine Language
Assembly Language
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Machine Language
In this language, instructions are written in binary from.
It is directly understood by the computer.
Programs written in this language are machine-dependent.
It is also known as first generation language.
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Assembly Language
In this language, symbols are used.
Symbols are called mnemonics.
Symbolic Language
It is mostly used for writing system software.
Second generation language.
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High-Level Language
Language that is close to human languages.
It is easier to write and modify.
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19. Categories of High Level Languages
Procedural Languages
Object-Oriented Languages
Non-procedural Languages
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Procedural Languages
Third generation languages
In these languages, program is a predefined set of instructions.
Popular procedural languages .
FORTRAN  FORmula TRANslation
BASIC  Beginner All Purpose Symbolic Instruction Code
COBOL  Common Business Oriented Language
PASCAL
C  Middle-level language
Application Software as well as System Software
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21. Object- Oriented Languages
Programs are written on the basis of objects.
Object  Collection of data and functions
Easier to learn and modify.
C++ and Java
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22. Features of Object-Oriented Programming
Objects
Classes
Real-world Modeling
Reusability
Information Hiding  Encapsulation
Polymorphism  Multiple ways
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Object-Oriented Language
Developed in 1980 at Bell Lab.
Improved version of C language.
Powerful language.
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History of C++
The C language was developed in late 60’s and early 70’s, in Bell Laboratories.
In those days BCPL and B languages were developed there.
The BCPL language was developed in 1967 by Martin Richards as a language for writing operating systems software and compilers.
In 1970 Ken Thompson used B language to create early versions of the UNIX operating system at Bell Laboratories.
Dennis Ritchie developed a general purpose language, called C language, by using different features of BCPL and B languages.
In the early 1980's, also at Bell Laboratories, another programming language was created which was based upon the C language.  This new language was developed by Bjarne Stroustrup and was called C++
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25. Difference b/w c and c++
When he designed C++, he added OOP (Object Oriented Programming) features to C without significantly changing the C component.  Thus C++ is a "relative" (called a superset) of C, meaning that any valid C program is also a valid C++ program.
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26. Non-Procedural Languages
Fourth-generation language
Need to tell computer “what to do” not “how to do”.
It is used in database application and report generation.
Important Non-procedural languages.
SQL  Structured Query Language
RPG  Report Program Generator
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27. Difference Between Low-Level & High-Level Languages
Low-Level Language
High-level language are easy to learn.
Low-level languages are difficult to learn.
Translator is required.
No translator is required.
Programs in high-level languages are slow in execution.
Programs in low-level languages are fast in execution.
Programs in high-level languages are easy to modify.
Programs in low-level languages are difficult to modify.
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28. Difference Between Low-Level & High-Level Languages
Low-Level Language
High-level languages are near to human languages.
Low-level languages are far from human languages.
High-level languages do not provide much facility at hardware level.
Low-level languages provide facility to write programs at hardware level.
Deep knowledge of hardware is not required to write programs.
Deep knowledge of hardware is required to write programs.
These languages are normally used to write application programs.
These languages are normally used to write hardware programs.
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29. Natural Programming Language
Fifth generation language
Very complex
Most of these languages are in experimental phase.
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Types of Codes
Source Code
Written in high-level language
Object Code
Translated by language processor.
Machine code
Computer can not understand source code but directly understands object code.
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31. Difference Between Source Code & Object Code
Source code is written in high-level or assembly language.
Object code is written in machine language through compilers.
Source code is easy to understand.
Object code is difficult to understand.
Source code is easy to modify.
Object code is difficult to modify.
Source code contains fewer statements than object code.
Object code contains more statements than source code.
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Language Processor
It is a software that converts high-level language into machine language.
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33. Types of Language Processor
Complier
Interpreter
Assembler
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Compiler
It converts source program as a whole into machine code / object program.
Compiler
Source Program
Object Program
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Interpreter
It converts one statement of a program at one time.
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Assembler
It translated the instruction of a assembly language into machine language.
Assembly Language
Program
Assembler
Object Program
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37. Difference Between Compiler & Interpreter
Compiler will stop translating if it finds an error and there will be no executable code generated.
Interpreter will execute all the lines before error and will stop at the line which contains the error.
Compiler compile the program as whole.
It converts one statement of a program at one time.
Compiler generate object file.
Interpreter generates no object file.
Compiler translation is fast.
Interpreter translation is slow.
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38. Programming Techniques
Structured Programming
Object-Oriented Programming
Event-Driven Programming
Visual Programming
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39. Structured Programming
A program is divided in small units called modules or sub-programs.
Sequential Structure
Control flows in logical sequence.
Conditional/ Selective structure
Selection on basis of condition
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40. Structured Programming (contd.)
Iterative / Repetitive Structure
Loops
Function Call
Control moves to block of code
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41. Advantages & Disadvantages of Structured Programming
Reusability
Easier to code
Easier to modify
Easier to maintain
Disadvantage
Difficult to separate data from functions.
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42. Object-Oriented Programming
Programs are written on the basis of objects.
Object
Collection of data and function
Easier to learn and modify
Examples:
C ++
Java
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43. Event-Driven Programming
Statements are executed in response to an event.
For Example: Clicking the mouse button.
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Visual Programming
Graphical user interface
User friendly interface
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Features of C++
It is very convenient language.
It is a well-structured language.
It is case sensitive language.
It provides machine independent.
It is an object oriented language.
In C++. A program can be divided into small modules.
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46. Basic Structure of C++ Program
The format of writing program in C++is known as its structure. It consists of following parts.
Pre-processor directive
Main( ) function
Program body  C++ statements
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47. Pre-processor Directive
It is an instruction given to the compiler before the execution of actual program.
Include preprocessor directive is used in C++ to include header files in the program.
# include <iostream.h>
Preprocessor
Directive
Header files
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Header Files
It is a collection of standard library functions to perform different tasks.
There are many header files for different purposes.
It must be included in the program before calling any of its function.
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Main ( ) Function
It is the starting point of a C++ program.
C++ statements are written in the body of the main () function.
void main( ) {
Body of the main function }
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C++ Statements
These are the instructions for the computer to perform a task.
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51. Basic Structure of C++ Program
# include <iostream.h> void main( ) { cout<<“Hello World”; }
Preprocessor Directive
Main function
C++ Statement
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Using ‘cout’
The cout object is used to print a message on the screen.
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Purpose of C++
Stroustrup states that the purpose of C++ is to make writing good programs easier and more pleasant for the individual
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versions of the C++
There are several versions of the C++ language, of which Visual C++ is only one.  Other dialects include Borland C++, Turbo C++, and Code Warrior (Mac). 
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LAB WORK
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