Simple but Interesting Features of VS2010 and C# 4.0

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Routing;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Page.MetaKeywords = "Test keywords";
        Page.MetaDescription = "Test description";
        if (!IsPostBack)
        {
            string test = Page.RouteData.Values["Name"].ToString();
            txtData.Text = test;
            if (!string.IsNullOrWhiteSpace(test))
            {
                txtData.Text = test;
                divVal1.InnerHtml = OptionalPara(1, Val2: "Named Val 2", Val1: "Named Val 1");//named type order is changed
                divVal2.InnerHtml = OptionalPara(2, Val2: "val2");
                divVal3.InnerHtml = OptionalPara(3);
                
            }
            else
            {
                txtData.Text = "Parameter appears to be blank :)";
            }
            UseDynamic();
            UseIsNullorWhiteSpace();
        }

    }
    protected void btnBack_Click(object sender, EventArgs e)
    {
        Response.Redirect(ResolveUrl("~/MySecondPage/") + "An");
    }

    public string  OptionalPara(int a, string Val1=null, string Val2 = null)
    
    {
        string newVal=string.Empty;
        if (!string.IsNullOrWhiteSpace(Val1) && !string.IsNullOrWhiteSpace(Val2))
            newVal = "a= " + a + ", Val1= " + Val1 + ", Val2= " + Val2;
        else if (!string.IsNullOrWhiteSpace(Val1))
                newVal = "a= " + a + ", Val1= " + Val1;
            else if (!string.IsNullOrWhiteSpace(Val2))
                newVal = "a= " + a + ", Val2= " + Val2;
            else
                newVal = "a= " + a;

              return newVal;


    }
    public void UseDynamic()
    {
        dynamic intValue = 1;
        dynamic strValue = " is my roll no.";
        dynamic result = intValue + strValue;
        divUseDynamic.InnerHtml = result;
    }

    public void UseIsNullorWhiteSpace()
    {
        bool stEmpty = string.IsNullOrWhiteSpace(string.Empty); //true
        bool stReguSpace = string.IsNullOrWhiteSpace("   "); // true
        bool stChar1 = string.IsNullOrWhiteSpace("\n\t"); //true
        bool stChar2 = string.IsNullOrWhiteSpace("\r\n\v "); //true
        bool stNull = string.IsNullOrWhiteSpace(null); //true
        bool stData = string.IsNullOrWhiteSpace("Test String"); //false
    }

}