This is a very important question which usually ask in the interviews.
Let us discuss-
Answer- This question have very simple answer that .Tostring() can’t handle the null value but Convert.ToString can.
Example 1- understand it with the help of program.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebApplication2
{
public partial class Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Session["Name"] = null;
string Name=Session["Name"].ToString();
}
}
}
Explanation- We can see in above example that there is a session which have null value, when we apply .ToString() it will throw Exception ‘object reference not set to an instance of an object’
Example 2-
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebApplication2
{
public partial class Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Session["Name"] = null;
string Name= Convert.ToString( Session["Name"]);
}
}
}
Explanation- We can see in above example that there is a session which also have null value, when we apply Convert.ToString it will not throw Exception, it will handle it and sting ‘Name’ have empty string.
Author- Er. Rahul Kr. Yadav
Let us discuss-
Answer- This question have very simple answer that .Tostring() can’t handle the null value but Convert.ToString can.
Example 1- understand it with the help of program.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebApplication2
{
public partial class Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Session["Name"] = null;
string Name=Session["Name"].ToString();
}
}
}
Explanation- We can see in above example that there is a session which have null value, when we apply .ToString() it will throw Exception ‘object reference not set to an instance of an object’
Example 2-
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebApplication2
{
public partial class Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Session["Name"] = null;
string Name= Convert.ToString( Session["Name"]);
}
}
}
Explanation- We can see in above example that there is a session which also have null value, when we apply Convert.ToString it will not throw Exception, it will handle it and sting ‘Name’ have empty string.
Author- Er. Rahul Kr. Yadav