This table lists the features introduced in C# versions 8 - 12 and indicates whether they are available out of the box, require additional polyfills, or require a runtime.
| Feature | Out of the Box | Require polyfills | Require Runtime |
|---|---|---|---|
| Non-nullable references | ✔️ | ❌ | ❌ |
| Switch Expressions | ✔️ | ❌ | ❌ |
| Property pattern matching | ✔️ | ❌ | ❌ |
| Positional pattern matching | ✔️ | ❌ | ❌ |
| Static local functions | ✔️ | ❌ | ❌ |
| Using declarations | ✔️ | ❌ | ❌ |
| Null-coalescing assignment | ✔️ | ❌ | ❌ |
| Read-only members | ✔️ | ❌ | ❌ |
| Asynchronous streams | ✔️ | ❌ | ❌ |
| Indices and Range | ❌ | ✔️ | ❌ |
| Default interface methods | ❌ | ❌ | ✔️ |
| Feature | Out of the Box | Require polyfills | Require Runtime |
|---|---|---|---|
| Records | ✔️ | ❌ | ❌ |
| Target-typed new expressions | ✔️ | ❌ | ❌ |
| Static Anonymous Functions | ✔️ | ❌ | ❌ |
| Pattern matching enhancements | ✔️ | ❌ | ❌ |
| Lambda discard parameters | ✔️ | ❌ | ❌ |
| Target-typed conditional expressions | ✔️ | ❌ | ❌ |
| Target-typed new | ✔️ | ❌ | ❌ |
| ExtensionGetEnumeratorSupportForeachLoopsExample | ✔️ | ❌ | ❌ |
| Native integers | ✔️ | ❌ | ❌ |
| Module initializers | ✔️ | ❌ | ❌ |
| Attributes on local functions | ✔️ | ❌ | ❌ |
| Function pointers | ✔️ | ❌ | ❌ |
| Attributes on parameters | ✔️ | ❌ | ❌ |
| Positional properties | ❌ | ✔️ | ❌ |
| Init-only properties | ❌ | ✔️ | ❌ |
| CallerArgumentExpression | ❌ | ✔️ | ❌ |
| Suppress emitting locals init | ❌ | ✔️ | ❌ |
| Covariant return types | ❌ | ❌ | ✔️ |
| Feature | Out of the Box | Require polyfills | Require Runtime |
|---|---|---|---|
| Implicit Usings | ✔️ | ❌ | ❌ |
| Global using directives | ✔️ | ❌ | ❌ |
| File-scoped namespaces | ✔️ | ❌ | ❌ |
| Extended property patterns | ✔️ | ❌ | ❌ |
| Record structs | ✔️ | ❌ | ❌ |
| Improved lambda support | ✔️ | ❌ | ❌ |
| Interpolated strings improvements | ✔️ | ❌ | ❌ |
| Constant interpolated strings | ✔️ | ❌ | ❌ |
| Mixed interpolated verbatim strings | ✔️ | ❌ | ❌ |
| [Async methods improvements] | ✔️? | ❌ | ❌ |
| Feature | Out of the Box | Require polyfills | Require Runtime |
|---|---|---|---|
| Raw string literals | ✔️ | ❌ | ❌ |
| Auto default struct | ✔️ | ❌ | ❌ |
| UTF 8 string literals | ✔️ | ❌ | ❌ |
| File local types | ✔️ | ❌ | ❌ |
| Extended nameof scope | ✔️ | ❌ | ❌ |
| Generic attribute | ✔️ | ❌ | ❌ |
| Pattern matching span | ✔️ | ❌ | ❌ |
| Required members | ❌ | ✔️ | ❌ |
| List patterns | ❌ | ✔️ | ❌ |
| Static abstract members | ❌ | ❌ | ✔️ |
| Feature | Out of the Box | Require polyfills | Require Runtime |
|---|---|---|---|
| CollectionExpressionExample | ✔️ | ❌ | ❌ |
| Primary Constructors | ✔️ | ❌ | ❌ |
| ref readonly parameters | ✔️ | ❌ | ❌ |
| Alias for any type | ✔️ | ❌ | ❌ |
| Optional Lambda expression parameters | ✔️ | ❌ | ❌ |
| Inline array | ❌ | ❌ | ✔️ |