Introduction to C# and .NET

• C# is a versatile, object-oriented programming language developed by Microsoft.

• It is designed to work within the .NET framework, which supports cross-platform development and a wide range of libraries and tools.

Basic Syntax and Structure

• C# programs typically consist of one or more classes, which are defined using the class keyword.

• Every C# program has a Main method, which is the application's entry point.

• Statements are terminated with a semicolon (;).

• Comments can be single-line (//) or multi-line (/* */).

Variables and Data Types

• Variables in C# must be declared with a data type, such as int, float, double, char, string, or bool.

  
  

• Variables can be assigned a value using the assignment operator (=).

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Operators

• C# supports various operators, including arithmetic (+, -, *, /, %), comparison (==, !=, <, >, <=, >=), logical (&&, ||, !), and assignment (=, +=, -=, *=, /=, %=).

Control Structures

• C# has several control structures, such as if, else, switch, while, do-while, and for.

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Object-Oriented Programming (OOP) in C#

• C# supports object-oriented programming with classes, objects, inheritance, polymorphism, and encapsulation.

• Classes are defined with the class keyword and have properties, methods, and constructors.

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• Objects are instances of classes created using the new keyword.

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Inheritance

• Inheritance allows a class to inherit properties and methods from a base class, promoting code reuse and modularity.

• In C#, inheritance is defined using the : symbol.

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Polymorphism

• Polymorphism allows methods to have different implementations based on the object they are called on.

• In C#, polymorphism can be achieved through method overriding (using the override keyword) and interfaces.

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These are the key concepts covered in

the C# Fundamentals and Object-Oriented Programming topics for Week 1, Day 2. Below are some additional topics to be aware of:

Encapsulation

• Encapsulation is the practice of hiding an object's implementation details and exposing only what is necessary.

• In C#, encapsulation can be achieved through access modifiers (public, private, protected, and internal) and properties (getters and setters).

Example:

Interfaces

• Interfaces define contracts that classes can implement, ensuring a consistent structure and behaviour.

• In C#, interfaces are defined using the interface keyword and are implemented by classes using the : symbol.

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Generics

• Generics allow you to create type-agnostic classes, methods, and interfaces that work with various data types.

• In C#, generics are defined using angle brackets (<>) and can be constrained using the where keyword.

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LINQ (Language Integrated Query)

• Using a consistent syntax, LINQ allows you to query data from various sources (such as collections, databases, and XML files).

• In C#, LINQ queries can be written using query syntax or method syntax.

Example:

These concepts form the basis of C# programming and object-oriented programming. Be sure to practice and reinforce your understanding with hands-on exercises and projects.