namespace ConsoleApp1

{

    using System;

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("".PadRight(100, '*'));

            Console.WriteLine("Compiler interns constant literals (therefore s1 and s2 will be the same instance)");

            Console.WriteLine("".PadRight(100, '*'));

​

            string s1 = "abc";

            string s2 = "abc";

            Console.WriteLine("s1 = " + s1);

            Console.WriteLine("s2 = " + s2);

​

            Console.WriteLine("s1 is interned: " + (string.IsInterned(s1) != null));

            Console.WriteLine("s2 is interned: " + (string.IsInterned(s2) != null));

​

            Console.WriteLine("s1 is equal to s2: " + string.Equals(s1, s2));

            Console.WriteLine("s1 is equal reference to s2: " + object.ReferenceEquals(s1, s2));

​

            Console.WriteLine();

            Console.WriteLine("".PadRight(100, '*'));

            Console.WriteLine("Concatenating 'd' to both strings, without interning 'abcd', will create 2 different instances");

            Console.WriteLine("".PadRight(100, '*'));

            s1 = s1 + "d";

            Console.WriteLine("s1 = " + s1);

            Console.WriteLine("s1 is interned: " + (string.IsInterned(s1) != null));

            s2 = s2 + "d";

            Console.WriteLine("s2 = " + s2);

            Console.WriteLine("s2 is interned: " + (string.IsInterned(s2) != null));

​

            Console.WriteLine("s1 == s2: " + string.Equals(s1, s2));

            Console.WriteLine("s1 === s2: " + object.ReferenceEquals(s1, s2));

​

            Console.WriteLine();

            Console.WriteLine("".PadRight(100, '*'));

            Console.WriteLine("Interning 'abcd' (s1) and creating new strings, will reuse the interned instance");

            Console.WriteLine("".PadRight(100, '*'));

            //s2 = string.Intern(s1);

            string s3 = "ab" + "cd";

            string s4 = "a" + "bcd";

            Console.WriteLine("s3 = " + s3);

            Console.WriteLine("s4 = " + s4);

​

            Console.WriteLine("s1 is interned: " + (string.IsInterned(s1) != null));

            Console.WriteLine("s2 is interned: " + (string.IsInterned(s2) != null));

            Console.WriteLine("s3 is interned: " + (string.IsInterned(s3) != null));

            Console.WriteLine("s4 is interned: " + (string.IsInterned(s4) != null));

​

            Console.WriteLine("s1 ==  s3: " + string.Equals(s1, s3));

            Console.WriteLine("s1 === s3: " + object.ReferenceEquals(s1, s3));

            Console.WriteLine("s1 ==  s4: " + string.Equals(s1, s4));

            Console.WriteLine("s1 === s4: " + object.ReferenceEquals(s1, s4));

            Console.WriteLine("s2 ==  s3: " + string.Equals(s2, s3));

            Console.WriteLine("s2 === s3: " + object.ReferenceEquals(s2, s3));

            Console.WriteLine("s2 ==  s4: " + string.Equals(s2, s4));

            Console.WriteLine("s2 === s4: " + object.ReferenceEquals(s2, s4));

            Console.WriteLine("s3 ==  s4: " + string.Equals(s3, s4));

            Console.WriteLine("s3 === s4 " + object.ReferenceEquals(s3, s4));

            //Console.ReadLine();

        }

    }

}

​