params

Hi Ravi,


The params keyword allows methods to have a variable length parameter list.

For example, the following class defines a method called "MultiPrint", which can have any number of string's passed to it.

using System;
public class MyApplication
{

   public static void MultiPrint(params string[] list)
   {
      for ( int i = 0 ; i < list.Length ; i++ )
         Console.WriteLine(list[i]);
   }

   public static void Main()
   {
    MultiPrint("First", "Second", "Third");

    MultiPrint("Fourth");

    MultiPrint("Fifth", "Sixth");

   }
}


Running this program prints out:

First

Second

Third

Fourth

Fifth

Sixth

There can only be one params keyword per method declaration, and it can only be on the final parameter in the list.

Parameter array in vb.net

 

Condition of using this array

1.It must be the lone argument in the parameter declaration or it is used only once.

2.It is passed by call by value.

3.It must be the one dimensional array.

4.It must be the last argument in the parameter declaration.

5.A keyword param array is used after by val.

 

Program

Public Class Form1

 

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        sname("Student Name", "raj", "ravi", "abhijit", "rahul", "adarsh")

    End Sub

    Private Sub sname(ByVal s As String, ByVal ParamArray ar() As String)

        Dim i As Integer

        TextBox1.Text += s + vbCrLf

        For i = 0 To UBound(ar)

            TextBox1.Text += ar(i) + vbCrLf

        Next

 

    End Sub

 

End Class

Output

Student Name
raj
ravi
abhijit
rahul
adarsh

Please refer the below link

http://www.csharpfriends.com/articles/getarticle.aspx?articleid=49

Thanks

The 'params' keyword is used to indicate that an argument to a method is a parameter array i.e. it can consist of not one but several values of the same type, separated by commas. A parameter array must be the last (or only) argument to a method.

Check this link for an example:

http://msdn.microsoft.com/en-us/library/w5zay9db.aspx