C# 14, a planned update to Microsoft’s cross-platform, general purpose programming language, adds an extension member syntax to build on the familiar feature of extension methods.
Extension members allow developers to “add” methods to existing types without having to create a new derived type, recompile, or otherwise modify the original type. The latest C# 14 preview, released with .NET 10 Preview 3, adds static extension methods and instance and static extension properties, according to Kathleen Pollard, principal program manager for .NET at Microsoft, in a May 8 blog post.
Extension members also introduce an alternative syntax for extension methods. The new syntax is optional, and developers do not need to change their existing extension methods. Regardless of the style, extension members add functionality to types. This is particularly useful if developers do not have access to the type’s source code or if the type is an interface, Pollard said. If developers do not like using !list.Any(), they can create their own extension method IsEmpty(). Starting in the latest preview, developers can make that a property and use it just like any other property of the type. Using the new syntax, developers also can add extensions that work like static properties and methods on the underlying type.
