Named parameters allow you to pass parameters into a function in any order and are near essential when using C#'s other new feature: optional parameters. To use a named parameter, simply specify the parameter name followed by a colon and then the value you are passing into a function.
Here is a method where Message1 and Message2 are required and Message3 is optional
private void Message(string Message1, string Message2, string Message3 = "Hello")
{ }
Above method can be called in following different ways:
Message("R1", "R2");
Message(Message1:"R1",Message2:"R2");
//Optional parameters must appear after required parameters
Message("R1", "R2","Hello World");
//Names parameters
Message(Message1: "R1", Message2: "R2", Message3 :"Hello World");