Object-Oriented Programming- An Introduction
Lecture 1B
08/01/25
Prof. Anita Agrawal
2 1/8/2025 7:09:01 PM
Modern Programming Languages
First modern language- C
High-Level Statements were written in English
Replaced assembly code
Faster,Efficient and more structured. Splits tasks into
smaller ones.
But however heavily dependent on procedure and
syntax- hence huge complex programs, with clumsy code
Anita Agrawal CS F213
3 1/8/2025 7:09:01 PM
o Good for simple programs- But bigger the program, more
lengthy and tougher to manage by programmers.
Anita Agrawal CS F213
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Procedural: More focus on functions
Object-Oriented: More focus Aon
simple real-world analogy
objects
Anita Agrawal CS F213
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Procedural Programming vs Object
Oriented Programming
The unit in procedural programming is function, and unit in object-
oriented programming is class.
Procedural programming concentrates on creating functions,
while object-oriented programming starts from isolating the
classes, and then looking for the methods inside them.
Anita Agrawal CS F213
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OOP why????
Computer scientists have struggled for decades to design
new languages and techniques for writing software.
Procedural languages existed but unfortunately, experience
has shown that writing for large systems was virtually
impossible.
Small programs seemed to be no problem, but scaling to
large systems with large programming teams could result in
$100M projects that never worked and were thrown out.
Anita Agrawal CS F213
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The only solution seemed to lie in writing small software
units that could communicate via well-defined interfaces
and protocols like computer chips.
The units must be small enough that one developer can
understand them entirely and most importantly the units
must be protected from interference by other units so
that programmers can code the units in isolation
The Object-Oriented paradigm fits these guidelines as
designers represent complete concepts or real world
entities as objects with approved interfaces for use by
other objects.
Anita Agrawal CS F213
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The first object-oriented language (called Simula), was
designed in the 1960's, but object-oriented
programming has only come into fashion in the 1990’s.
Simula, short for "simulation language," was the first
object-oriented programming language.
Anita Agrawal CS F213
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OOP
Object-Oriented Programming is a programming
paradigm based on the concept of
“objects” and “classes”
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Object Oriented Programming
Languages
Java, C++, C#, Ruby, etc.
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Object
Is a software bundle of related state and behavior.
Software objects are often used to model the real-
world objects that you find in everyday life.
Anita Agrawal CS F213
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Class
A class is a blueprint or prototype from which
objects are created.
A class models the state and behavior of the
object.
It represents the set of properties or methods that are
common to all objects of one type.
Anita Agrawal CS F213
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Object…..
It is a basic unit of Object Oriented Programming and
represents the real life entities.
It consists of :
State
Behavior
Identity
Anita Agrawal CS F213
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State- It is represented by attributes of an object. It
also reflects the properties of an object.
These are the instance variables. Each object will have its
unique set of instance variables.
An object’s state is created by the values assigned to these
instance variables
Behaviour - It is represented by methods of an
object. It also reflects the response of an object to
other objects.
Identity-It gives a unique name to an object and
enables one object to interact with other objects.
Anita Agrawal CS F213
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Method:
A class may contain many methods.
Itis in methods that the logics are written, data is
manipulated and all the actions are taken.
Anita Agrawal CS F213
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Class
members
A Class
Anita Agrawal -Dog
CS F213
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An example of an Object- Dog
Anita Agrawal CS F213
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The 4 fundamental OOP Concepts
1. Data Abstraction
2. Encapsulation
3. Polymorphism (dynamic binding)
4. Inheritance (particular case of polymorphism )
Anita Agrawal CS F213
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Data Abstraction
It deals with hiding the details and showing the essential
things to the user.
In Java, abstraction is accomplished using Abstract classes
and interfaces.
An example of abstraction- A Banking application, where
only required data fields are revealed to the user.
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Only necessary fields are available to the user
rest are hidden.
Anita Agrawal CS F213
