How to Store data without using Database and how to retrieve them?

Question

I am parsing the html file to extract tabular information through column names. And I want like let user give the input for column name. And according to that column names t

Answer 1

Lots of people have been talking about XML, it's a good idea. However, if Linq is available for you, you shoudl really consider using Linq to XML instead of SAX/DOM parsing.

Linq to XML makes it easier to parse, create and edit XML file compared to SAX and DOM parser. Using SAX/DOM parsing usually requires a lot of loops to get to the correct element or to navigate trough the nodes.

Example taken from MSDN :
Using DOM Parsing :

XmlDocument doc = new XmlDocument();
XmlElement name = doc.CreateElement("Name");
name.InnerText = "Patrick Hines";
XmlElement phone1 = doc.CreateElement("Phone");
phone1.SetAttribute("Type", "Home");
phone1.InnerText = "206-555-0144";        
XmlElement phone2 = doc.CreateElement("Phone");
phone2.SetAttribute("Type", "Work");
phone2.InnerText = "425-555-0145";        
XmlElement street1 = doc.CreateElement("Street1");        
street1.InnerText = "123 Main St";
XmlElement city = doc.CreateElement("City");
city.InnerText = "Mercer Island";
XmlElement state = doc.CreateElement("State");
state.InnerText = "WA";
XmlElement postal = doc.CreateElement("Postal");
postal.InnerText = "68042";
XmlElement address = doc.CreateElement("Address");
address.AppendChild(street1);
address.AppendChild(city);
address.AppendChild(state);
address.AppendChild(postal);
XmlElement contact = doc.CreateElement("Contact");
contact.AppendChild(name);
contact.AppendChild(phone1);
contact.AppendChild(phone2);
contact.AppendChild(address);
XmlElement contacts = doc.CreateElement("Contacts");
contacts.AppendChild(contact);
doc.AppendChild(contacts);

Using Linq to XML :

XElement contacts =
    new XElement("Contacts",
        new XElement("Contact",
            new XElement("Name", "Patrick Hines"),
            new XElement("Phone", "206-555-0144", 
                new XAttribute("Type", "Home")),
            new XElement("phone", "425-555-0145",
                new XAttribute("Type", "Work")),
            new XElement("Address",
                new XElement("Street1", "123 Main St"),
                new XElement("City", "Mercer Island"),
                new XElement("State", "WA"),
                new XElement("Postal", "68042")
            )
        )
    );

Easier to do and much more clear.

Edit:
Save the XML tree to contacts.xml :

// using the code above
contact.Save("contacts.xml");

Load the contacts.xml file :

//using the code above
XDocument contactDoc = XDocument.Load("contacts.xml"); 

To update an element of the tree there is a few functions in the doc that can do it depending on what you want to do