Saravanan Madheswaran
TL;DR: Discover 7 underrated C# 12 and C# 13 features like collection expressions, inline arrays, and params collections that boost code clarity, performance, and maintainability. Master these hidden gems now to prepare your codebase for C# 14 and stay ahead with modern C# development practices.
Introduction
C# 14 is approaching fast, and developers who master the hidden gems from C# 12 and C# 13 will have a significant advantage. While features like primary constructors dominated headlines, several game-changing additions flew under the radar, and they’re transforming how we write performant, maintainable code.
These underrated features deliver real improvements to developer productivity, application performance, and code readability. Whether you’re building desktop or mobile applications, or working with component libraries like Syncfusion’s Essential Studio®, mastering these capabilities will elevate your development skills and prepare you for C# 14’s advanced features.
C# 12 features you shouldn’t miss
1. Collection expressions: Simplified instantiation
What it does: Enables initializing collections using clean bracket syntax without calling constructors directly or repeating type declarations.
// Old way:
var listA = new List { 1, 2, 3 };
// New way (C# 12):
List listB = [1, 2, 3];
This streamlined syntax aligns C# with modern languages like Python and JavaScript, making code more readable and concise. It’s particularly valuable when working with data visualizations or building chart configurations in libraries like Syncfusion®.
2. Inline arrays: Struct-level optimization
This feature is a performance optimization powerhouse for systems and high-performance code.
What it does: Enables defining small, fixed-size arrays inside structs using the InlineArray attribute, dramatically improving memory locality and performance.
Why it matters: It eliminates heap allocations and reduces memory fragmentation, which is critical for high-performance rendering and UI component operations.
[System.Runtime.CompilerServices.InlineArray(8)]
public struct ByteBuffer
{
private byte _element0;
}
For applications requiring real-time performance, such as financial dashboards built with Syncfusion® components, inline arrays help eliminate garbage collection pauses.
3. Ref readonly parameters: Better immutability
What it does: Allows passing large structs by reference while maintaining immutability, avoiding expensive copying operations.
public void Process(ref readonly LargeStruct data)
{
// ...
}
This feature is invaluable when working with charting libraries where you’re passing complex geometry, styling data, or large datasets to rendering components. It clearly communicates intent while optimizing performance.
4. Using aliases for any type: Clean code boost
This one’s a hidden gem, especially for library maintainers.
What it does: Extends using aliases beyond namespaces to support any type, including complex generic types, tuples, and arrays.
using DataSeries = List<(int A, int B)>;
DataSeries series = [
(1, 2),
(3, 4),
(5, 6)
];
This hidden gem significantly improves API readability, especially in component libraries where complex generic types are common.
Common mistake: Many developers think using aliases are only for classes or namespaces but it works for complex types, too!
C# 13 features to master before C# 14
5. Typed exceptions: More precise error handling
What it does: Extends the params keyword to work with any collection type that implements IEnumerable<T>, not just arrays.
// Method signature specifies it can throw specific exceptions
public string ProcessData() throws FileNotFoundException, InvalidDataException
{
// Implementation
}
// Caller must handle the potential exceptions
try
{
var result = ProcessData();
}
catch (FileNotFoundException fnf)
{
// Handle missing file
}
catch (InvalidDataException ide)
{
// Handle invalid data
}
At Syncfusion®, we’ve found that this is incredibly valuable for developers, as it is crucial for building robust applications.
6. Params span: Performance-friendly variadic functions
What it does: Enables variadic functions (methods that take a variable number of arguments) without the allocations required by traditional params arrays.
// Traditional params method (causes allocation)
public void Process(params int[] values)
{
// ...
}
// C# 13 params span (allocation-free)
public void ProcessFast(params ReadOnlySpan<int> values)
{
// ...
}
For high-performance components like real-time data grids, this feature will allow more efficient API design without sacrificing developer convenience.
7. Warning wave 7: Subtle, yet powerful
What it does: Introduces new compiler warnings grouped as “waves” for gradual adoption, helping identify potential code improvements and modernization opportunities.
<LangVersion>preview</LangVersion>
<WarningLevel>7</WarningLevel>
It includes helpful diagnostics such as detecting obvious refactorings or unsafe casts. Though it’s not a language syntax feature, warning wave 7 helps teams adopt clean coding practices iteratively, which is essential when maintaining large frameworks like our Essential Studio®.
How do these features enhance modern development?
At Syncfusion®, we continuously explore how language advancements can enhance our component libraries. These features translate to real benefits:
- Collection expressions make defining chart data and configurations more intuitive.
- Inline arrays improve performance in data visualization components.
- Ref readonly parameters optimize our rendering pipelines.
- Type aliases create cleaner, more readable APIs.
- Typed exceptions help developers better understand and handle error conditions.
- Params span reduces allocations in performance-critical methods.
These features collectively enable us to build more performant, maintainable components while improving the developer’s experience.
Preparing your codebase for C# 14
As C# 14 approaches, mastering these underrated features from C# 12 and C# 13 will position you to take full advantage of the language’s evolution. Here’s how you can prepare:
- Upgrade your projects to .NET 7/8 to access C# 12 features.
- Install the latest preview SDK to experiment with C# 13 features.
- Enable preview language features in your project file:
<PropertyGroup>
<LangVersion>preview</LangVersion>
</PropertyGroup>
- Refactor existing code to use these modern patterns where appropriate
Many upcoming C# 14 features will build upon these foundations, making your investment in learning them immediately valuable.
Conclusion – Building for the Future
The underrated C# 12 and C# 13 features we’ve explored offer tangible improvements to code quality, performance, and developer productivity. As C# 14 approaches, developers who embrace collection expressions, inline arrays, params collections, and other hidden gems will be perfectly positioned to leverage the next wave of language innovations.
Ready to modernize your C# skills and explore these features in action? Check out our latest Essential Studio® release on the license and downloads page. If you’re new to Syncfusion®, we offer a 30-day free trial —the perfect opportunity to test these powerful features and see how modern C# capabilities enhance component performance and developer productivity.
If you have questions, contact us through our support forum, support portal, or feedback portal. We are always happy to assist you!
No spam, just valuable updates.
