Introduction to C# Programming

Study Notes

C# is a modern, high-level, general-purpose, object-oriented programming language.
It serves as the principal language for the .NET framework, which is a platform for developing software applications.
.NET framework includes predefined classes and functions for processing input, managing hardware devices, and interacting with system software.
C# allows the creation of applications across standalone, web-based, and mobile APIs, making it versatile for multiple devices.

An ATM is an example of a class. It requires an object, such as an inserted card, to function.
When a card (object) is inserted into an ATM (class), it retrieves information like account details and balance.
Operations, such as withdrawing money or checking balances, are methods of the ATM class and can only be accessed through an object.

A class acts as a user-defined blueprint or prototype from which objects are created.
Example: Automobile as a class, with subclasses including Car, Bus, and Bike.
Specific examples of objects from classes include:
- Car class: Polo, i20
- Bus class: Quantum, Minibus
- Bike class: Scooter, Cruiser

An object is an instance derived from a created class, each with its own state and behavior.
An object's state represents the data it holds, while its behavior is often defined by methods.

A class can represent an individual, such as a Person, and define attributes (name, height, weight, gender, age) and behaviours (walking, running, jumping, speaking, sleeping).
Each object of the class can have different attributes while sharing the same set of behaviors.

Classes are declared using the keyword class, followed by the class name, with members enclosed in curly braces.
Key components of a class include:
- Access modifiers (private, public, internal) that dictate access rules.
- Class keyword and name.
- Class members comprising properties, data fields, and methods operating on the data.