null reference exception- NullReferenceException in c#

NullReferenceException

If you are trying to access an object, but object have null values that time give the an null reference exception

For example.

static void Main()
{
         DataSet ds=new DataSet;
         ds=null;

    if (ds.Table.Length == 0) // here is an exception
    {
        // some logc here....
    }
}


Output:

System.NullReferenceException: Object reference not set to an instance of an object.

Other example

static void Main()
{
    string str = null;
    if (str.Length == 0) // here is an exception
    {
        // some logc here....
    }
 }


Output:

System.NullReferenceException: Object reference not set to an instance of an object.