Written By David Reed
C# 14 features, introduced alongside .NET 10 in early 2025, provide developers with tools to simplify code syntax, improve performance, and expand language capabilities. In this blog, we cover the most important C# 14 features and provide examples to help you get started quickly.
Field-Backed Properties: Simplifying Property Implementation
Previously, implementing properties with custom logic required explicit backing fields, resulting in verbose code. C# 14 introduces the field keyword, allowing direct access to the compiler-generated backing field within property accessors. This reduces boilerplate code and improves clarity.
Example Before C# 14:
private string _message;
public string Message
{
get => _message;
set => _message = value ?? throw new ArgumentNullException(nameof(value));
}
With C# 14:
public string Message
{
get;
set => field = value ?? throw new ArgumentNullException(nameof(value));
}
By using field, developers can implement custom logic without declaring explicit backing fields, enhancing maintainability.
Implicit Conversions for Span and ReadOnlySpan
C# 14 adds first-class support for Span<T> and ReadOnlySpan<T>, including implicit conversions between arrays and span types. This simplifies memory manipulation and improves performance in scenarios requiring low-level memory access.
Example:
int[] numbers = { 1, 2, 3, 4, 5 };
ReadOnlySpan<int> readOnlySpan = numbers;
This feature is particularly useful for performance-critical applications where explicit conversions would otherwise clutter code.
nameof Expression Supports Unbound Generic Types
The nameof expression in C# 14 now supports unbound generic types, making it easier to retrieve generic type names without specifying type arguments. This helps with code refactoring, logging, and diagnostics.
Example:
string typeName = nameof(Dictionary<,>); // Evaluates to "Dictionary"
This small enhancement simplifies code that relies on type names and improves maintainability.
Modifiers on Simple Lambda Parameters
C# 14 allows parameter modifiers like ref, in, out, and scoped in lambda expressions without explicit types. This improves readability and enables more flexible functional programming patterns.
Example:
delegate bool TryParse<T>(string text, out T result);
TryParse<int> parse = (string text, out result) => int.TryParse(text, out result);
This feature makes lambdas more versatile and concise.
Experimental Feature: String Literals in Data Section
An experimental feature lets string literals be emitted as UTF-8 data into a separate section of the PE file, optimizing storage and retrieval. Developers can test this to potentially reduce assembly size and improve runtime performance.
Conclusion
The C# 14 features are designed to help developers write more concise, maintainable, and efficient code. By leveraging these enhancements, applications can benefit from improved performance and cleaner syntax, making them ready to take full advantage of the latest .NET ecosystem improvements.
For more details on practical applications and expert guidance, check out KTL Solutions’ .NET development services or explore the official Microsoft C# documentation.