C# Versions

C# Versions

The history of C# from MS

C# version 1.0

When you go back and look, C# version 1.0, released with Visual Studio .NET 2002. The major features of C# 1.0 included: 

• Classes
• Structs
• Interfaces
• Events
• Properties
• Delegates
• Operators and expressions
• Statements
• Attributes

C# version 1.2

C# version 1.2 shipped with Visual Studio .NET 2003. It contained a few small enhancements to the language. Most notable is that starting with this version, the code generated in a foreach loop called Dispose on an IEnumerator when that IEnumerator implemented IDisposable.

C# version 2.0

Now things start to get interesting. Let's take a look at some major features of C# 2.0, released in 2005, along with Visual Studio 2005:

• Generics
• Partial types
• Anonymous methods
• Nullable value types
• Iterators
• Covariance and contravariance

Other C# 2.0 features added capabilities to existing features:

• Getter/setter separate accessibility

• Method group conversions (delegates)

• Static classes

• Delegate inference

C# version 3.0

C# version 3.0 came in late 2007, along with Visual Studio 2008, though the full boat of language features would actually come with .NET Framework version 3.5. This version marked a major change in the growth of C#. It established C# as a truly formidable programming language. Let's take a look at some major features in this version:

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

C# version 4.0

C# version 4.0, released with Visual Studio 2010. The next version did introduce some interesting new features:

• Dynamic binding
• Named/optional arguments
• Generic covariant and contravariant
• Embedded interop types

C# version 5.0

C# version 5.0, released with Visual Studio 2012, was a focused version of the language: the async and await model for asynchronous programming. Here is the major features list: 

• Asynchronous members
• Caller info attributes

See Also,

• Code Project: Caller Info Attributes in C# 5.0

C# version 6.0

With versions 3.0 and 5.0, C# had added major new features in an object-oriented language. With version 6.0, released with Visual Studio 2015. Here are some of them:

• Static imports
• Exception filters
• Auto-property initializers
• Expression bodied members
• Null propagator
• String interpolation
• nameof operator

Other new features include,

• Index initializers
• Await in catch/finally blocks
• Default values for getter-only properties

C# version 7.0

C# version 7.0 was released with Visual Studio 2017. Here are some of the new features:

• Out variables
• Tuples and deconstruction
• Pattern matching
• Local functions
• Expanded expression bodied members
• Ref locals and returns

Other features included:

• Discards
• Binary Literals and Digit Separators
• Throw expressions

C# version 7.1

C# started releasing point releases with C# 7.1. This version added the languageversion selection configuration element, three new language features, and new compiler behavior.

The new language features in this release are:

• asyncMain method

  • The entry point for an application can have the async modifier.

• default literal expressions

  • You can use default literal expressions in default value expressions when the target type can be inferred.

• Inferred tuple element names

  • The names of tuple elements can be inferred from tuple initialization in many cases.

• Pattern matching on generic type parameters

  • You can use pattern match expressions on variables whose type is a generic type parameter.

Finally, the compiler has two options -refout and -refonly that control reference assembly generation.

C# version 7.2 

C# 7.2 added several small language features,

• Techniques for writing safe efficient code

  • A combination of syntax improvements that enable working with value types using reference semantics.

• Non-trailing named arguments

  • Named arguments can be followed by positional arguments.

• Leading underscores in numeric literals

  • Numeric literals can now have leading underscores before any printed digits.

• private protected access modifier

  • The private protected access modifier enables access for derived classes in the same assembly.

• Conditional ref expressions

  • The result of a conditional expression (?:) can now be a reference.

C# version 7.3

There are two main themes to the C# 7.3 release. The following new features support the theme of better performance for safe code:

• You can access fixed fields without pinning.
• You can reassign ref local variables.
• You can use initializers on stackalloc arrays.
• You can use fixed statements with any type that supports a pattern.
• You can use additional generic constraints.

The following enhancements were made to existing features,

• You can test == and != with tuple types.

• You can use expression variables in more locations.

• You may attach attributes to the backing field of auto-implemented properties.

• Method resolution when arguments differ by in has been improved.

• Overload resolution now has fewer ambiguous cases.

The new compiler options are,

• -publicsign to enable Open Source Software (OSS) signing of assemblies.

• -pathmap to provide a mapping for source directories.

What's new in C# 8.0

• 04/07/2020

C# 8.0 adds the following features and enhancements to the C# language,

• Readonly members

• Default interface methods

• Pattern matching enhancements:

  • Switch expressions

  • Property patterns

  • Tuple patterns

  • 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# 8.0 is supported on .NET Core 3.x and .NET Standard 2.1. For more information, see C#language versioning.

What's new in C# 9.0

• 04/07/2021

C# 9.0 adds the following features and enhancements to the C# language:

• Records

• Init only setters

• Top-level statements

• Pattern matching enhancements

• Performance and interop

  • Native sized integers

  • Function pointers

  • Suppress emitting localsinit flag

• Fit and finish features

  • 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

• Support for code generators

  • Module initializers

  • New features for partial methods

C# 9.0 is supported on .NET 5. For more information, see C#language versioning.