Checking session if empty or not

Question

I want to check that session is null or empty i.e. some thing like this:

if(Session[\"emp_num\"] != null)
{

   if (!string.IsNullOrEmpty(Session[\"emp_num\"         


        

Answer 1

You need to check that Session["emp_num"] is not null before trying to convert it to a string otherwise you will get a null reference exception.

I'd go with your first example - but you could make it slightly more "elegant".

There are a couple of ways, but the ones that springs to mind are:

if (Session["emp_num"] is string)
{
}

or

if (!string.IsNullOrEmpty(Session["emp_num"] as string))
{
}

This will return null if the variable doesn't exist or isn't a string.