Learn CSHARP with Real Code Examples

using System;
using System.Collections.Generic;
using System.Linq;

public class Person {
    public string Name { get; set; }
    public int Age { get; set; }
    public string City { get; set; }
}

class Program {
    static void Main() {
        var people = new List<Person> {
        new Person { Name = "Alice", Age = 25, City = "New York" },
        new Person { Name = "Bob", Age = 30, City = "London" },
        new Person { Name = "Charlie", Age = 35, City = "New York" }
        };

        var adults = people
        .Where(p => p.Age >= 30)
        .OrderBy(p => p.Name)
        .Select(p => new { p.Name, p.Age })
        .ToList();

        foreach (var person in adults) {
        Console.WriteLine($"{person.Name} is {person.Age} years old");
        }
    }
}

Shows modern C# features including LINQ, auto-properties, and string interpolation.

using System;

public class Car {
    public string Model { get; set; }
    public int Year { get; set; }
    public void ShowInfo() {
        Console.WriteLine($"Car: {Model}, Year: {Year}");
    }
}

class Program {
    static void Main() {
        Car car = new Car { Model = "Tesla", Year = 2023 };
        car.ShowInfo();
    }
}

Defines a class with properties and methods, then creates and uses objects.

using System;
using System.Collections.Generic;

class Program {
    static void Main() {
        List<string> fruits = new List<string> { "Apple", "Banana", "Cherry" };
        fruits.ForEach(f => Console.WriteLine(f));
    }
}

Demonstrates iterating over a list using ForEach and lambda expressions.

using System;
using System.Collections.Generic;

class Program {
    static void Main() {
        Dictionary<string, int> ages = new Dictionary<string, int> {
        {"Alice", 25},
        {"Bob", 30}
        };
        foreach (var kvp in ages) {
        Console.WriteLine($"{kvp.Key} is {kvp.Value} years old");
        }
    }
}

Shows using Dictionary to store key-value pairs and iterate over them.

using System;
using System.Collections.Generic;
using System.Linq;

class Program {
    static void Main() {
        List<int> numbers = new List<int> { 1, 2, 3, 4, 5 };
        var evenSquares = numbers.Where(n => n % 2 == 0).Select(n => n * n).ToList();
        evenSquares.ForEach(n => Console.WriteLine(n));
    }
}

Filters and projects data from a list using LINQ methods.

using System;

class Program {
    static void Main() {
        int? nullableNumber = null;
        int value = nullableNumber ?? 10;
        Console.WriteLine(value);
    }
}

Demonstrates nullable types and using the ?? operator.

using System;
using System.Threading.Tasks;

class Program {
    static async Task Main() {
        await PrintMessageAsync();
    }

    static async Task PrintMessageAsync() {
        await Task.Delay(1000);
        Console.WriteLine("Hello after 1 second!");
    }
}

Demonstrates async and await for asynchronous operations.

using System;

class Program {
    static void Main() {
        string name = "Alice";
        int age = 25;
        Console.WriteLine($"{name} is {age} years old");
    }
}

Demonstrates using string interpolation to embed expressions inside strings.

using System;

public class Book {
    public string Title { get; set; }
    public string Author { get; set; }
    public Book(string title, string author) {
        Title = title;
        Author = author;
    }
}

class Program {
    static void Main() {
        Book book = new Book("1984", "George Orwell");
        Console.WriteLine($"{book.Title} by {book.Author}");
    }
}

Defines a class with a constructor and uses it to initialize properties.

using System;

class Publisher {
    public event Action OnChange;
    public void RaiseEvent() {
        OnChange?.Invoke();
    }
}

class Program {
    static void Main() {
        Publisher p = new Publisher();
        p.OnChange += () => Console.WriteLine("Event triggered!");
        p.RaiseEvent();
    }
}

Demonstrates a simple event and delegate usage in C#.