using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
     class Book
     {
          public string BookName { set; get; }
          public int Price { set; get; }
     }

     class Program
     {
          static void Main(string[] args)
          {
               // Method 1 (Create List with completed books)
               List<Book> books1 = new List<Book>()
               {
                    new Book() { BookName = "Lord of the Rings", Price = 200 },
                    new Book() { BookName = "The Three Musketeers", Price = 300 },
                    new Book() { BookName = "Harry Potter", Price = 400 },
               };

               // Method 2 (Create List then we add books )
               List<Book> books2 = new List<Book>();
               books2.Add(new Book() { BookName = "Lord of the Rings", Price = 200 });
               books2.Add(new Book() { BookName = "The Three Musketeers", Price = 300 });
               books2.Add(new Book() { BookName = "Harry Potter", Price = 400 });
          }
     }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
     struct MyPoint
     {
          public int X;
          public int Y;
     }

     class Program
     {
          static void Main(string[] args)
          {
               // Method 1 (Create List with filled elements MyPoint)
               List<MyPoint> points1 = new List<MyPoint>()
               {
                    new MyPoint() { X = 10, Y = 200 },
                    new MyPoint() { X = 30, Y = 400 },
                    new MyPoint() { X = 50, Y = 700 },
               };

               // Method 2 (Create List then add elements MyPoint)
               List<MyPoint> points2 = new List<MyPoint>();
               points2.Add( new MyPoint() { X = 10, Y = 200 });
               points2.Add( new MyPoint() { X = 30, Y = 400 });
               points2.Add( new MyPoint() { X = 50, Y = 700 });
          }
     }
}