Different Types Of Method Parameters in C#

Method parameter is one of the integral part of programming and it also applies with C# programming Language.

We can categorize method parameters in various parts. Some of them are:

• Named Parameters (C# 4.0 and above)
• Ref Parameter (Passing Value Types by Reference)
• Out Parameters
• Default Parameters or Optional Arguments (C# 4.0 and above)
• Dynamic parameter (dynamic keyword).
• Value parameter or Passing Value Types by Value (normal C# method param are value parameter)
• Params (params)

Named Parameters

In C# 4.0 a new type of argument iis introduced known as named parameter. Using this feature we can specify the value of a parameter by parameter name regardless of its ordering in method. I am using a simple method to explain it. Have a look at the following screenshot.



It provides an ease for user because sometimes we may have 10-20 parameters in a method. In that case we need to remember ordering of all those parameters. But if we use the default parameter feature of C# then we do not need to remember any ordering. This feature is available in C# 4.0 and above versions (C#, C# 6).

Suppose we have a method like the following code snippet,

• Named parameter provide us the facility to do not remember the parameter ordering.
• Improves the readability of code.
• Easy to understand.
• Due to readability it also reduces the chances of bug in application.

Disadvantages of Named Parameter

• Its performance is slower as compared to fixed argument. It should be avoided if it does not change the readability and understanding of code to a great extent.
• Due to slower performance we can also say that it is syntactic sugar over fixed parameter calls.

Default Parameters or Optional Arguments (C# 4.0 and above)

In C# 4.0 along with named parameter another method parameter feature introduced known as Default Parameters or Optional Arguments. Default parameter can be used with method, constructor, delegates and indexer. For method, constructor, delegates and indexer we can specify which parameter is required (fixed) and which is optional. Any call can omit arguments for optional parameter but it must specify the value for required (fixed) parameter.





Optional parameter must be defined after any required parameter.

While calling the method having optional parameter if we provide value for an optional parameter then we must provide value for all preceding optional parameters.

E.g.