C# Tutorial

This C# tutorial helps you learn C# programming from scratch and shows you how to apply C# to develop your next great application.

Getting started

  • What is C# – introduces the C# programming language and the .NET
  • Install Visual Studio 2022 – guides you on how to install Visual Studio 2022 Community Edition to start programming C#.
  • C# Hello World – shows you step by step how to create the first C# program that displays the Hello, World! message on the console window.
  • C# syntax – introduces to you the basic C# syntax, including identifiers, keywords, literals, statements, and comments.

Variables & types

  • Variables – shows you how to declare variables and use them to hold data in the program.
  • integer – introduces the integral types in C# that hold integer numbers.
  • float – explains the floating-point number types, including decimal, double, and float.
  • char – covers the character type that represents a single character.
  • string – discusses the string type and guides you on the basic string operations.
  • Raw strings – learns how to use raw strings to make your code more readable.
  • bool – learns how to use the bool type to represent boolean values: true and false.
  • var – shows you how to use the var keyword to declare implicit-typed variables.

Control flow

  • if – learns how to check a condition and execute a block if a condition is true.
  • if else – shows you how to check multiple conditions and execute a block if a condition is true or another block otherwise.
  • if else if – learns how to check multiple conditions and execute a block if a condition is true.
  • switch – selects a statement for execution if an expression matches a pattern.
  • while – learns how to use the while loop statement to conditionally execute a block of code zero or more times.
  • do while – shows you how to use the do while statement to execute a block one or more times based on a condition.
  • for – guides you on how to execute a block a specified number of times.
  • break – show you how to terminate prematurely using the break statement.
  • continue – learns how to start a new loop iteration prematurely using the continue statement.

Functions

  • Functions – guides you on how to modulize the program and make the code reusable by using functions.
  • Default parameters – learns how to simplify the function call using default parameters.

Arrays

  • Array – shows you how to use an array to store a fixed number of elements of the same type.
  • Multidimensional arrays – learns how to create multidimensional arrays, including 2D and 3D arrays.
  • foreach – guides you on how to use the foreach statement to iterate over the elements of an array.
  • Passing an array to a function – shows you how to pass an array to a function as an argument.
  • List patterns – shows you how to match an array or a list with a sequence using list patterns.

Classes

  • Class – learns about classes and objects, defines a class, and creates objects from the class.
  • this keyword – explains the this keyword in C#.
  • public vs. private – guides you on how to use the access modifiers public and private, and how to use them effectively.
  • Constructor – shows you how to define constructors to initialize objects.
  • Property – learns how to use a property that provides a flexible way to read, write, and compute the value of a private field.
  • Constant – introduces constants and how to define them in a method or class.
  • Indexer – shows you how to use an indexer to allow an object to be indexed like an array.
  • Object initializer – learns how to initialize accessible fields and properties of an object using an object initializer.
  • init – specifies an accessor method in a property or indexer that allows assigning a value to the property or indexer element only during object initialization.

Static members & classes

  • Static field and property – explains the static fields and properties and how to use them effectively.
  • Static method – learns about static methods and how to use them to define a utility class.
  • Static constructor – shows you how to define a static constructor that initializes static members.
  • Static class – guides you on how to use a static class to define a utility class.

Inheritance

  • Inheritance – shows you how to define a class that inherits properties and methods of another class.
  • Inheritance & constructor – explains the constructor calling order and shows you how to use the base() syntax to call a specific constructor in the base class.
  • new modifier – explains the new modifier and how to use it to explicitly hide the member in the base class from the subclass.
  • virtual modifier – shows you how to use the virtual modifier to modify a member of a base class and discuss the differences between new and override methods.
  • sealed modifier – guides you on the sealed classes and sealed properties and methods.
  • Casting – explains how to convert a reference from one type to another using casting, including upcasting and downcasting.
  • Abstract classes – introduces you to the abstract classes with practical examples.
  • Object – learns about the object that is the base class of all the classes.
  • Anonymous types – shows you how to create an anonymous object with a set of read-only properties without defining a class first.

Interfaces

  • Interface – introduces interfaces and how to use interfaces to make the application more flexible and extensible.
  • Default implementation – shows you how to provide a default implementation for an interface member to make the application backward compatible.
  • Explicit Interface Implementation – discusses two ways of implementing interfaces and when to implement interfaces explicitly.
  • Extending interfaces – guides you on how to define an interface that extends a single interface or multiple interfaces.
  • Abstract classes vs. interfaces – learns how to choose when to use an interface or abstract class.

Exception handling

  • try…catch – learns about exceptions and how to use the try...catch statement to handle exceptions.
  • throwing an exception – shows you how to use the throw keyword to raise an exception in the application.
  • try…catch…finally – shows you how to use the try...catch...finally statement to handle exceptions and clean up resources.
  • Rethrow exceptions – learns how to catch an exception and rethrow it using the throw statement.
  • Custom exceptions – guides you on how to create and use custom exceptions that provide more information about the exception that occurs.
  • Handling global unhandled exception – shows you how to handle the global unhandled exception by subscribing to the UnhandledException event.

Generics

  • Generics – learns how to use generics to write reusable and type-neutral code.
  • Generic Classes – shows you how to define reusable & type-neutral classes.
  • Generic Constraints – specifies what types can be used as the type parameters of the generic types.
  • Covariance – shows you how to use covariance to define a method that can return a more specific type than what is defined in the method signature.
  • Contravariance – guides you on how to use contravariance to define a method that can accept an argument that is less specific than what is defined in the method signature.

Delegates & Events

  • Delegates – introduces you to delegates and how to use them to pass methods to other methods as arguments.
  • Anonymous Methods – guides you on creating anonymous methods.
  • Lambda Expressions – learns how to use lambda expressions to create anonymous functions.
  • Events – learns about C# events and how to use the publisher/subscriber pattern to handle events.
  • Method group conversion to delegate – explains to you what a method group is and how the method group conversion to delegate process works.

Namespace, Assembly, and Assembly Scope

  • namespace– discusses the namespace in depth so that you can organize a large codebase into smaller logical units
  • internal – learns how to use the internal keyword to allow access to a type and its members within the same assembly.

Extension Methods

  • Extension methods – learns how to add a method to an existing type without using inheritance.

Working with Date & Time

  • DateTime – shows you how to represent multiple values as a single variable.
  • DateTime.Parse() – converts a date string to a DateTime object based on a specified culture setting.
  • DateTime.ParseExact() – converts a date string to a DateTime object based on an exact format.
  • TimeSpan – represents a time interval using the TimeSpan object.
  • DateTimeOffset – introduces to you the DateTimeOffset that includes a DateTime and an offset that represents the difference between the local time and UTC.
  • DateOnly – learns how to use the DateOnly type to represent the date-only data.
  • TimeOnly – shows you how to use the TimeOnly type to represent the time of the day effectively.

Advanced C# Types

  • C# value types and reference types – understands the value types and reference types.
  • NullReferenceException – deals with NullReferenceException exception that occurs at runtime of the program.
  • Nullable Value Type – discusses the nullable value type and how to use it effectively.
  • Tuples– shows you how to represent multiple values as a single variable.
  • Records – guides you on records that provide built-in functionality for encapsulating data, making it easy to work with immutable and strong-typed data.