It's a common misconception that string is a value type. 
That's because its immutability  makes it act sort of like 
a value type. It actually acts like a normal reference type

//string is a refference type but it behavious like a value
//type.
//following programe show both charactersitic of string.
using System;
class a
{
    public static void Main(String [] args)
     {
          String str1="hello";
          String str2=str1;
          String str3="hello";
         Console.WriteLine(str1);
         Console.WriteLine(str2);
         if(str1==str3)
           {
               Console.WriteLine("str1 anb str3 are 
equal ");
            }
      }
}

string is both type it depends on use

string is reference type but it behaves as value
type.Because every time u assign a value to string a new
object is created.

String is a reference type

string is referrence type....
bcz there is no limitations of string means it can have variable length......thats why str[0],str[1],
string stores only the referrence to the value stored in it....

String is reference type .