C# .NET Method Parameter Modifiers

All the Methods, both static and instance level, tend to take parameters passed in by the caller. However, unlike some programming languages, C# provides a set of parameter modifiers that control how arguments are sent into (and possibly returned from) a given method, as shown in the Table.

Parameter Modifier	Meaning
(none)	If a parameter is not marked with a parameter modifier, it is assumed to be passed by value, meaning the called method receives a copy of the original data.
out	Output parameters are assigned by the method being called (and therefore passed by reference). If the called method fails to assign output parameters, you are issued a compiler error.
params	This parameter modifier allows you to send in a variable number of identically typed arguments as a single logical parameter. A method can have only a single params modifier, and it must be the final parameter of the method.
ref	The value is initially assigned by the caller, and may be optionally reassigned by the called method (as the data is also passed by reference). No compiler error is generated if the called method fails to assign a ref parameter.