Partilhar via


C# 4.0 : Optional Parameters

Days of creating multiple overloads to avoid parameters are gone. You no more have to create many methods and pass the default one there. C# 4.0 brings to us the concept of “optional” parameters.

How it works, let’s check it. Suppose you have a method like below,

public static class TestClass

{

   public static void ParamMethod(string Name, double Salary,

string Department, int Age = 30)

   {

       Console.WriteLine("Name = {0}", Name);

       Console.WriteLine("Age = {0}", Age);

       Console.WriteLine("Salary = {0}", Salary);

       Console.WriteLine("Department = {0}", Department);

   }

}

Here you have mentioned the default value using “=” for the parameter “Age”.

Rule!!! You always have to put optional parameters after the “non-optional” parameters.

Now if you write the below code and call the method ParamMethod, you can omit the “optional parameter” Age.

class Program

{

   static void Main(string[] args)

   {

       TestClass.ParamMethod("Wriju", 1000.00, "Software");

   }

}

Will give you the below output,

Name = Wriju

Age = 30

Salary = 1000

Department = Software

Namoskar!!!

Comments

  • Anonymous
    February 27, 2009
    PingBack from http://www.anith.com/?p=14163

  • Anonymous
    May 21, 2009
    "Days of creating multiple overloads to avoid parameters are gone." Not yet :) but as soon as 4.0 comes out they will be, it just doens't feel right to me when CTPs/Betas are referred to as being ready and available for use.