Object-Oriented Programming (OOP Concept)

Object-oriented programming (OOP) it is generally a computer science term used to characterize a programming language that began development in the year 1960’s. OOP is widely accepted as being far more flexible than other computer programming languages. The term ‘object-oriented programming’ was originally coined by Xerox PARC to designate a computer application that describes the methodology of using objects as the foundation for computation. In other words it a computer science term which is used to describe a computer application that is composed of multiple objects which are connected to each other. Traditionally most computer programming languages were simply a group of functions or instructions.

Object Oriented Programming Overview If you are not familiar with an object-oriented programming language you will first need to understand the foundation that makes up this paradigm. It is a necessity for anyone who plans on writing code. Object Oriented Programming Traditionally programming languages have been divided into two categories and these are data and procedures which are carried out on data. By itself data is static. It will not be static when procedures are carried out which can be altered. Understanding The Message Concept In OOPs To understand object oriented programming you will need to become familiar with messages. As the name implies a message is a process in which software objects will communicate with one another. Because of this having one object is not enough.

Object oriented programming organizes a program around its data i.e. objects and a set of well defined interface to that data. An Object-oriented program can be characterized as data controlling access to code.

Concepts of Object Oriented Programming are:

Objects

Data abstraction

Data Encapsulation

Inheritance

Overloading

Polymorphism

Cascading Style Sheets

Cascading Style Sheets is a simple mechanism for adding Styles to the wed documents. (for e.g. color, fonts, spacing etc.). Before going thought the CSS you should have a basic understanding of the HTML/XHTML.

What is CSS?

CSS stands for Cascading Style Sheets

Styles define how to display HTML elements

External Style Sheets can save a lot of work

External Style Sheets are stored in CSS files

Styles were added to HTML 4.0 to solve a problem

Styles are normally stored in Style Sheets

Multiple style definitions will cascade into one

To solve this problem, the World Wide Web Consortium (W3C) - responsible for standardizing HTML - created CSS in addition to HTML 4.0. With HTML 4.0, all formatting can be removed from the HTML document and stored in a separate CSS file.

There are three parts for CSS syntax: a sector, a property and a value.

The sector is normally the HTML elecment or a tag which can be defined and property is the attribute which can be changed and each property can be taken a value. The property and value are separated by a colon, and surrounded by curly braces.

Syntax:- Sector { property:value}

Example :- body {color:black}