Every single feature of C# in 10 minutes

Introduction

This tutorial provides a concise overview of C# programming language features, designed for beginners and those transitioning from other programming languages. By the end, you will have a solid understanding of C# syntax, data types, object-oriented programming concepts, and control flow statements.

Step 1: Understanding the Basics of C#

• C# is part of the C family of programming languages, utilizing curly brackets and semicolons.
• Developed by Microsoft, it is open-source and cross-platform, allowing applications to run on Windows, Linux, Mac, mobile (via Xamarin), and WebAssembly (via Blazor).

Step 2: Declaring Functions and Variables

• Functions in C# have a return type, a name, and can take arguments. The body is enclosed in curly brackets, and statements end with a semicolon.

  void MyFunction(int parameter) {
      // function body
  }
  

• Use the static keyword for static functions.
• Variables can be declared with specific types or using var for implicit typing, where the compiler determines the type:

  var myString = "Hello"; // Compiler infers string type
  var myNumber = 42;      // Compiler infers int type
  

Step 3: Exploring Data Types

• C# has built-in data types such as integers, floating-point numbers, and strings.

• You can create custom data types using:

  • Classes: Defined with the class keyword.
  • Structs: More efficient for primitive data types, stored on the stack.
  • Records: Immutable data types that define a shape with fields.

  Example of a record:

  public record Person(string Name, int Age);
  

Step 4: Using Access Modifiers

• Classes in C# can have five access modifiers:
  • public: Accessible from anywhere.
  • private: Accessible only within the declaring class.
  • protected: Accessible within the declaring class and derived classes.
  • internal: Accessible within the same assembly.
  • file: Accessible only within the same file.

Step 5: Implementing Object-Oriented Principles

• C# supports inheritance, allowing classes to derive from others.
• Use the abstract keyword for classes that should only be inherited.
• Interfaces define methods and properties that implementing classes must contain, declared with the interface keyword.

Step 6: Working with Properties and Constructors

• Properties can be declared using get and set for encapsulation:

  public string Name { get; set; }
  

• Constructors initialize a new instance of a class:

  public MyClass(string name) {
      Name = name;
  }
  

• Destructors clean up resources when an object is no longer needed.

Step 7: Control Flow Statements

• Use if, else if, and else for conditional logic.
• The switch statement can handle multiple conditions and pattern matching.
• Looping structures include:
  • for loops
  • while loops
  • foreach loops for iterating over collections.

Step 8: Utilizing Collections

• C# offers arrays and various collections from the System.Collections namespace, such as:
  • List<T>: A dynamic array.
  • Dictionary<TKey, TValue>: A key-value pair collection.

Step 9: Async Programming and Generics

• Use async and await keywords for asynchronous code:

  public async Task MyAsyncMethod() {
      await Task.Delay(1000);
  }
  

• Generics allow for type-safe data structures and methods:

  public class GenericClass<T> where T : class {
      // Class implementation
  }
  

Conclusion

You have now covered the essential features of C#, including its syntax, data types, object-oriented programming, control flow structures, and collections. To start coding in C#, install an IDE such as Visual Studio or Visual Studio Code, create a new console application using the command dotnet new console, and begin experimenting with the concepts learned. For further learning, check out more resources and tutorials on C#.