Duct-typed extension methods Example 8

Example8.cs

// Example 8: add a new instance

// This is just a dummy class that we can use in the example
public class City
{
  public City(string name, int population, string country)
  {
    Name = name;
    Population = population;
    Country = country;
  }

  public string Name { get; }
  public int Population { get; }
  public string Country { get; }
}

// This is a very specific extension method for adding a city to a list
public static void Add(this List<City> list, string name, int population, string country)
=> list.Add(new City(name, population, country));

// now create a list of cities, without writing `new City`
var cities = new List<City> 
{
  { "Chongqing", 30_751_600, "China" },
  { "Shanghai", 24_256_800, "China" },
  { "Delhi", 11_034_555, "India" },
  { "Beijing", 21_516_000, "China" },
  { "Dhaka", 14_399_000, "Bangladesh" }
};

// Output each item, to see if things work correctly
foreach(var city in cities)
{
  Console.WriteLine($"{city.Name}: {city.Population} ({city.Country})");
}