Lecture 1 – Introduction to Programming Paradigms

Programming Paradigms

Learn the fundamentals of Programming Paradigms understand the difference between procedural and object-oriented programming, explore real-world examples, and master the basics of variables, data types, and control structures to build a strong foundation in modern software development.

What is a Programming Paradigm?

A programming paradigm is a style or way of writing programs.
It defines how we think about problems and how we organize our code to solve them.

There are different paradigms, but the two most common are:

• Procedural Programming
• Object-Oriented Programming (OOP)

Procedural Programming

In procedural programming, the focus is on functions or procedures step-by-step instructions that tell the computer what to do.

You write code as a sequence of actions:

1. Get input
2. Process it
3. Produce output

The data and the functions that operate on that data are separate.

Example (C++)

#include <iostream>
using namespace std;

int addNumbers(int a, int b) {
    return a + b;
}

int main() {
    int x = 5, y = 10;
    int sum = addNumbers(x, y);
    cout << "Sum is: " << sum << endl;
    return 0;
}

Here, everything is based on functions.
Data (x, y) and logic (addNumbers) are independent.

Drawback:

As projects grow, managing hundreds of functions and variables becomes confusing.
No clear way to connect data and behavior of real-world entities.

Object-Oriented Programming (OOP)

OOP solves this problem by organizing everything around objects which combine data and behavior. Each object represents something real (like a car, student, or account) and knows how to act.

Key Pillars of OOP:

1. Encapsulation – Bundle data and methods together.
2. Inheritance – Reuse properties and methods of existing classes.
3. Polymorphism – Same action behaves differently based on the object type.
4. Abstraction – Show only the necessary details, hide the rest.

Understanding the C++ Programming Environment: A Step-by-Step Guide

Why OOP? (Advantages)

Procedural	Object-Oriented
Focus on actions	Focus on objects
Data & logic separate	Data + logic together
Hard to scale	Easy to maintain & extend
Code repetition	Code reuse via inheritance
Example: calculator program	Example: banking system, game, website backend

Real-World Example

Imagine you’re designing a Bank System.

Procedural Way:

You’ll create functions:

deposit();
withdraw();
checkBalance();

You’ll also manage variables like accountNumber, balance, name, etc.
All scattered and independent.

OOP Way:

You’ll create a class:

class BankAccount {
public:
    string name;
    double balance;

    void deposit(double amount) {
        balance += amount;
    }
    void withdraw(double amount) {
        balance -= amount;
    }
};

Now, every object (account) can:

• store its own data
• perform its own actions

int main() {
    BankAccount acc1;
    acc1.name = "Ali";
    acc1.balance = 1000;
    acc1.deposit(500);
    cout << acc1.name << " has $" << acc1.balance;
}

Data and logic live together → like in real life.

Basic Syntax Recap

Before diving deep into OOP, students must recall fundamental syntax used in both C++ and Java.

Variables:

int age = 20;
float price = 10.5;
string name = "Ali";

Data Types:

Type	Description	Example
int	Whole numbers	10
float/double	Decimal numbers	3.14
char	Single character	‘A’
string	Sequence of characters	“Hello”
bool	True/False	true

Control Structures:

If-Else:

if (age >= 18) {
    cout << "You are an adult";
} else {
    cout << "You are a minor";
}

Loops:

for (int i = 0; i < 5; i++) {
    cout << i << " ";
}

While:

int n = 1;
while (n <= 3) {
    cout << n << " ";
    n++;
}

Summary of Lecture 1

Concept	Meaning	Example
Programming Paradigm	Way of thinking/writing code	Procedural vs. OOP
Procedural	Focus on functions	addNumbers(a,b)
OOP	Focus on objects	BankAccount.deposit()
Advantage	Real-world modeling, reusability	Classes and objects
Syntax Recap	Data types, variables, loops	int, for, if

Positive Thought for Students:

“Every great programmer was once a beginner who refused to give up. Keep learning, keep experimenting because every line of code you write brings you one step closer to mastery.”