using System;

​

public class Program

{

    public static void Main()

    {

        int a = 2;

        int b = 5;

        // + Operator

        string result1 = "Addition of " + a + " + " + b + " is " + (a + b);

        //+ symbol actually translates to the string.Concat() method

        string result2 = string.Concat("Addition of ", a, " + ", b, " is ", (a + b));

        //OR

        string result3 = string.Concat(new object[] {"Addition of ", a, " + ", b, " is ", (a + b)});

        //string.Join() method

        string result4 = String.Join(String.Empty, new object[] {"Addition of ", a, " + ", b, " is ", (a + b)});

        //OR        

        string result5 = String.Join(String.Empty, "Addition of ", a, " + ", b, " is ", (a + b));

​

​

        // string.Format method

        string result6 = string.Format("Addition of {0} + {1} is {2}", a, b, (a + b));

        // string interpolation

        string result7 = $"Addition of {a} + {b} is {a + b}";

        // currency formatter "C"

        decimal saving = 786.78m;

        string result8 = $"My saving this month is {saving:C}.";

​

        Console.WriteLine($"+ : {result1}\n");

        Console.WriteLine($".Concat() : {result2}");

        Console.WriteLine($".Concat() : {result3}\n");

        Console.WriteLine($".Join() : {result4}");

        Console.WriteLine($".Join() : {result5}\n");

        Console.WriteLine($".Format() : {result6}\n");

        Console.WriteLine($"$ : {result7}");

        Console.WriteLine($"$ : {result8}");

    }

}