Question

Please how this string concatenation taking place?
i am really confuse what is happening why that slash i there and how the double quotes are used

SessionStateItemCollection items = new SessionStateItemCollection();

items["LastName"] = "Wilson";
items["FirstName"] = "Dan";

foreach (string s in items.Keys)
  Response.Write("items[\"" + s + "\"] = " + items[s].ToString() + "<br />");

//here i am looking for explanation please elaborate me on this please
Response.Write("items[\"" + s + "\"] = " + items[s].ToString() + "<br />");

Answer 1

The slash is escaping the quote. Basically it is going to write the name in quotes inside brackets. For your example the output would be:

items["Wilson"] = Wilson<br />

The escaping happens for the character directly after the backslash \. So \" is escaped to ". The following " is stopping the string and you are appending the s variable which in turn is the current item in the foreach loop.

Here is a article on escape characters.