public Building(int number, string address, string description = null) {
_description = description;
public string Address {get{ return _address;} set { _address = value;}}
public string Description {get{ return _description;} set { _description = value;}}
public static void Main()
var build1 = new Building(42, "Awesome St, 42", "good company");
var build2 = new Building(42, "Awesome St, 42", "bad company");
public static void PrintInfo(Building build){
Console.WriteLine("{0} : {1} ({2})", build.GetHashCode(), build.Address, build.Description);