.NET Language Features
Explore the powerful and expressive language features available in the .NET ecosystem. This section delves into the key constructs and advancements that enable developers to build robust, efficient, and maintainable applications.
C# Language Innovations
Pattern Matching
Pattern matching provides a more concise and powerful way to check types and extract data from objects. It simplifies conditional logic and data extraction.
Key features include:
- Type patterns
- Constant patterns
- Property patterns
- Positional patterns
- Relational patterns
- Logical patterns
// Example: Property pattern matching
public record Point(int X, int Y);
public void DisplayPointType(Point p)
{
if (p is { X: 0, Y: 0 })
{
Console.WriteLine("Origin");
}
else if (p is { X: var x, Y: var y } && x == y)
{
Console.WriteLine($"On the line X=Y with values {x}");
}
else
{
Console.WriteLine($"Point at ({p.X}, {p.Y})");
}
}
Records
Records simplify the creation of immutable data types. They automatically generate `Equals`, `GetHashCode`, `ToString`, and deconstruction methods, reducing boilerplate code.
// Immutable record type
public record Person(string FirstName, string LastName, int Age);
// Usage
var person = new Person("Jane", "Doe", 30);
Console.WriteLine(person); // Output: Person { FirstName = Jane, LastName = Doe, Age = 30 }
Record Structs
Similar to records, but defined as value types, offering performance benefits for small data structures.
Nullable Reference Types
A significant feature for improving code safety by distinguishing between reference types that can be null and those that cannot. This helps prevent `NullReferenceException` at compile time.
// Enable nullable reference types in your .csproj file:
// <Nullable>enable</Nullable>
string nonNullableString = "Hello";
// nonNullableString = null; // Warning CS8600: Converting null literal or possible null value to non-nullable type.
string? nullableString = null;
nullableString = "World"; // No warning
Default Interface Methods
Allows adding new members to interfaces without breaking existing implementations. Implementations can choose to override the new default behavior or use it as is.
Async Streams (.NET 6+)
Support for asynchronous iteration using IAsyncEnumerable<T> and the await foreach syntax, enabling efficient handling of asynchronous data sources.
Visual Basic .NET Enhancements
While C# often receives the spotlight for new features, Visual Basic .NET continues to evolve with modern programming paradigms.
- Async/Await support
- LINQ integration
- Anonymous types
- Lambda expressions
F# Functional Programming
F# is a powerful, open-source, functional-first programming language that runs on .NET. It excels in areas like data science, machine learning, and concurrent programming.
- Immutability by default
- Type inference
- Pattern matching
- Asynchronous workflows
- Computation expressions