using System; public class Coordinate { private int _x = 34; public int X { get { return _x; } set { _x = value; } } private readonly int _y = 89; public int Y { get { return _y; } } private readonly int _z; public int Z { get { return _z; } } public Coordinate() { _z = 42; } } public class Test { public static void Main() { Coordinate x = new Coordinate(); x.X = 123; } }