Comprehensive C# Course - Lecture Notes

Introduction

• This is a comprehensive, free full course on C#
• Covers hundreds if not thousands of examples
• No advertising during the course
• All code is available on GitHub

Tools and Installation

• Using Visual Studio Community
• Download from Visual Studio
• Works on both Windows and Mac
• The interface in Visual Studio can be customized via Tools > Options. Increase text size under Environment and Text Editor.

Setting Up a New Project

• Go to File > New > Project
• Select Visual C# and choose Console App (.NET Core) or other desired template
• Choose project location and name
• Click Create

First C# Program

• Writing a hello world program
• Using namespaces (using System;) to import classes and functions
• Defining a namespace and class
• Storing and printing values in Main method

Basic C# Concepts

Variables

• bool, int, long, decimal, double, and float data types
• Example: bool canIVote = true; int age = 30;
• Converting data types using parse and toString methods
• Use of escape characters (\n, \t, \\, etc.)

Arithmetic Operations

• Common arithmetic operations (+, -, *, /, %)
• Increment (++) and Decrement (--) operators
• Compound assignment operators (+=, -=, *=, /=, %=)

String Operations

• String Methods: Length, Contains, IndexOf, Remove, Insert, Replace, etc.
• StringBuilder for string manipulations without performance penalty
• String interpolation with $ and {}

Control Flow

If-Else

• Basic structure: if...else if...else
• Use relational (>, <, >=, <=, ==, !=) and logical (&&, ||, !) operators
• Example: Age-based school recommendations

Conditional (Ternary) Operator

• Syntax: condition ? consequence : alternative
• Example: string canDrive = age >= 16 ? "Yes" : "No";

Switch Case

• Uses: For when a variable needs to be compared against several values
• Basic format: switch(variable) { case value: //statements; break; ...}
• Example: School stages based on age

Loops

For Loop

• Basic format: for(initialization; condition; iteration) { //code }
• Example: Print numbers, generate index-based outputs

While Loop

• Runs as long as a condition is true
• Example: Print odd numbers

Do-While Loop

• Executes code block at least once before checking the condition
• Example: Number guessing game

Exception Handling

• Use try, catch, and finally blocks
• Example: Divide-by-zero error handling

Functions

• Avoid code duplication with functions
• Basics: access specifier return_type function_name(parameters) { //code }
• Example: Sum function returning integer or string based on parameters
• Named Parameters: Call functions with parameters out of order by naming them
• Method Overloading: Same function name, different parameters

Object-Oriented Programming

Classes and Objects

• Define real-world entities as code objects
• Example: Class Animal with attributes: name, sound, methods
• Constructors: Initialize objects with default or specific values
• Inheritance: Class Dog inherits Animal, add unique attributes

Properties and Encapsulation

• Properties with { get; set; }
• Encapsulate fields, provide controlled access

Interfaces

• Define contracts for classes to implement specific methods
• Example: IDrivable interface with methods Move, Stop

Delegates and Events

• Delegates: Reference methods; Example: Arithmetic operations
• Use delegate, lambda expressions
• Example: public delegate void Arithmetic(int x, int y);

Collections and Generics

Arrays and Lists

• Arrays: int[] array = new int[5];
• ArrayList: Dynamically sized, can hold mixed data types
• List<T>: Generic lists for specific data types

Dictionaries and Sets

• Store key-value pairs; Example: Dictionary<int, string> dict
• HashSet<T>: Unique collection of elements

Stacks and Queues

• Stack: LIFO (Last In First Out)
• Queue: FIFO (First In First Out)

LINQ (Language Integrated Query)

• Query collections of data
• Examples: from item in collection where condition select item
• Lambda Expressions: Simplify syntax for operations

Multithreading and Concurrency

• Create and manage multiple threads
• Example: Printing numbers with delay using Thread.Sleep(1000);
• Use lock for thread safety

Files and I/O Operations

• Read/Write data to files
• StreamReader and StreamWriter for handling text files
• BinaryReader and BinaryWriter for binary files

Working with Databases

Setting up SQL Server

• Installing SQL Server Developer
• Configuration for proper setup

Connecting to SQL Databases in C#

• Using Visual Studio: Configure data source, connection strings
• SQL Commands: Perform CRUD operations (Create, Read, Update, Delete)

Entity Framework

• ORM for database management
• Designing models and context to interact with databases

Advanced Concepts

Serialization

• Store object state in a stream; Example: Binary and XML serialization

Reflection

• Inspecting and interacting with object metadata at runtime

Conclusion

• By the end of this course, you should be among the most knowledgeable individuals in C# programming
• All code is on GitHub for reference and practice