csharplang/Language-Version-History.md

Features Added in C# Language Versions

C# 2 (VS 2005)

• Generics
• Partial types
• Anonymous methods
• Iterators
• Nullable types
• Getter/setter separate accessibility
• Method group conversions (delegates)
• Co- and Contra-variance for delegates and interfaces
• Static classes
• Delegate inference

C# 3 (VS 2008)

• Implicitly typed local variables
• Object and collection initializers
• Auto-Implemented properties
• Anonymous types
• Extension methods
• Query expressions
• Lambda expression
• Expression trees
• Partial methods

C# 4 (VS 2010)

• Dynamic binding
• Named and optional arguments
• Generic co- and contravariance
• Embedded interop types ("NoPIA")

C# 5 (VS 2012)

• Asynchronous methods
• Caller info attributes

C# 6 (VS 2015)

• Draft Specification online
• Compiler-as-a-service (Roslyn)
• Import of static type members into namespace
• Exception filters
• Await in catch/finally blocks
• Auto property initializers
• Default values for getter-only properties
• Expression-bodied members
• Null propagator (null-conditional operator, succinct null checking)
• String interpolation
• nameof operator
• Dictionary initializer

C# 7.0 (VS 2017)

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

C# 7.1 (tentative) (VS 2017 Update 3)

• Async main
• Default expressions
• Reference assemblies
• Inferred tuple element names
• Pattern-matching with generics