using System;

using System.Collections.Generic;

using System.Linq;

​

public class Student

{

    public int StudentID

    {

        get;

        set;

    }

​

    public string StudentName

    {

        get;

        set;

    }

​

    public int Age

    {

        get;

        set;

    }

}

​

public class Program

{

    public static void Main()

    {

        IList<String> strList = new List<String>() { "One", "Two", "Three", "Four", "Five"};

​

        var csv = strList.Aggregate((s1, s2) => s1 + "," + s2);

        Console.WriteLine(csv);

        // Student collection

        IList<Student> studentList = new List<Student>()

        {

            new Student()

            {

            StudentID = 1, StudentName = "John", Age = 13

            }

​

             , 

            new Student()

            {

            StudentID = 2, StudentName = "Moin", Age = 21

            }

​

             , 

            new Student()

            {

            StudentID = 3, StudentName = "Bill", Age = 18

            }

​

             , 

            new Student()

            {

            StudentID = 4, StudentName = "Ram", Age = 20

            }

​

             , 

            new Student()

            {

            StudentID = 5, StudentName = "Ron", Age = 15

            }

        };

​

        var aggregatedNames = studentList.Aggregate("Names: ", (acc, stud) => acc +=  stud.StudentName + ",");

        Console.WriteLine(aggregatedNames);

        var totalAge = studentList.Aggregate(0, (acc, stud) => acc +=  stud.Age);

        Console.WriteLine(totalAge);

        aggregatedNames = studentList.Aggregate("Names: ", (acc, stud) => acc +=  stud.StudentName + ",", (str => str.Substring(0, str.Length - 1)));

        Console.WriteLine(aggregatedNames);

    }

}