LanguageVersion Enum

The default language version, which is the latest supported version.

C# language version 1

C# language version 2

C# language version 3

Features: LINQ.

C# language version 4

Features: dynamic.

C# language version 5

Features: async, caller info attributes.

C# language version 6

Features:

• Using of a static class
• Exception filters
• Await in catch/finally blocks
• Auto-property initializers
• Expression-bodied methods and properties
• Null-propagating operator ?.
• String interpolation
• nameof operator
• Dictionary initializer

C# language version 7.0

Features:

• Out variables
• Pattern-matching
• Tuples
• Deconstruction
• Discards
• Local functions
• Digit separators
• Ref returns and locals
• Generalized async return types
• More expression-bodied members
• Throw expressions

C# language version 7.1

Features:

• Async Main
• Default literal
• Inferred tuple element names
• Pattern-matching with generics

C# language version 7.2

Features:

• Ref readonly
• Ref and readonly structs
• Ref extensions
• Conditional ref operator
• Private protected
• Digit separators after base specifier
• Non-trailing named arguments

C# language version 7.3

Features:

• Indexing fixed fields does not require pinning
• ref local variables may be reassigned
• stackalloc arrays support initializers
• More types support the fixed statement
• Enhanced generic constraints
• Tuples support == and !=
• Attach attributes to the backing fields for auto-implemented properties
• Method overload resolution improvements when arguments differ by 'in'
• Extend expression variables in initializers
• Improved overload candidates
• New compiler options (-publicsign and -pathmap)

C# language version 8.0

Features:

• Readonly members
• Default interface methods
• Pattern matching enhancements (switch expressions, property patterns, tuple patterns, and positional patterns)
• Using declarations
• Static local functions
• Disposable ref structs
• Nullable reference types
• Asynchronous streams
• Asynchronous disposable
• Indices and ranges
• Null-coalescing assignment
• Unmanaged constructed types
• Stackalloc in nested expressions
• Enhancement of interpolated verbatim strings

C# language version 9.0

Features:

• Records
• Init only setters
• Top-level statements
• Pattern matching enhancements
• Native sized integers
• Function pointers
• Suppress emitting localsinit flag
• Target-typed new expressions
• Static anonymous functions
• Target-typed conditional expressions
• Covariant return types
• Extension GetEnumerator support for foreach loops
• Lambda discard parameters
• Attributes on local functions
• Module initializers
• New features for partial methods

C# language version 10.0

Features:

• Record structs
• Global using directives
• Lambda improvements
• Improved definite assignment
• Constant interpolated strings
• Mix declarations and variables in deconstruction
• Extended property patterns
• Sealed record ToString
• Source Generator v2 APIs
• Method-level AsyncMethodBuilder

C# language version 11.0
Features:

• Raw string literals
• Static abstract members in interfaces
• Generic attributes
• Newlines in interpolations
• List-patterns
• Required members
• Span<char> constant pattern
• Struct auto-default
• Nameof(parameter)
• Checked user-defined operators
• UTF-8 string literals
• Unsigned right-shift operator
• Relaxed shift operator
• Ref fields
• File-local types

C# language version 12.0
Features:

• Primary constructors
• Using aliases for any types
• Nameof accessing instance members
• Inline arrays
• Collection expressions
• Ref readonly parameters
• Lambda optional parameters

C# language version 13.0
Features:

• Escape character
• Method group natural type improvements
• `Lock` object
• Implicit indexer access in object initializers
• `params` collections
• ref/unsafe in iterators/async
• `allows ref struct` constraint
• Partial properties

The latest major supported version.

Preview of the next language version.

The latest supported version of the language.