hashset

gistfile1.cs

        static void Main(string[] args)
        {
            bool success = false;
            HashSet<DataObject> set = new HashSet<DataObject>();
            DataObject myDataObject = new DataObject { foo = 1, bar = "bar" };
            success = set.Add(myDataObject);
            Console.WriteLine(set.Contains(myDataObject));
            myDataObject.foo = 2;
            Console.WriteLine(set.Contains(myDataObject));
            DataObject taken = set.First();
            Console.WriteLine(taken.Equals(myDataObject));
            Console.WriteLine(set.Contains(taken));
            Console.WriteLine(ReferenceEquals(taken, myDataObject));
            success = set.Add(taken);
            if (success) Console.Write("successfully "); else Console.Write("unsuccessfully ");
            Console.WriteLine("Added taken");
            Console.WriteLine(set.Count);
            foreach (DataObject obj in set)
            {
                Console.WriteLine(obj.ToString());
            }
            success = set.Add(new DataObject { foo = 1, bar = "bar" });
            if (success) Console.Write("successfully "); else Console.Write("unsuccessfully ");
            Console.WriteLine("Added new DataObject");
            foreach (DataObject obj in set)
            {
                Console.WriteLine(obj.ToString());
            }
            success = set.Add(new DataObject { foo = 1, bar = "bar" });
            if (success) Console.Write("successfully "); else Console.Write("unsuccessfully ");
            Console.WriteLine("Added new DataObject again");
            foreach (DataObject obj in set)
            {
                Console.WriteLine(obj.ToString());
            }
            success = set.Remove(taken);
            if (success) Console.Write("successfully "); else Console.Write("unsuccessfully ");
            Console.WriteLine("removed taken from set");
            foreach (DataObject obj in set)
            {
                Console.WriteLine(obj.ToString());
            }
            success = set.Remove(taken);
            if (success) Console.Write("successfully "); else Console.Write("unsuccessfully ");
            Console.WriteLine("removed taken from set");
            foreach (DataObject obj in set)
            {
                Console.WriteLine(obj.ToString());
            }
            Console.WriteLine(set.Contains(taken));
            Console.WriteLine(set.Count);
            Console.ReadLine();
        }
    }

    public class DataObject
    {
        public int foo { get; set; }
        public string bar { get; set; }

        public override int GetHashCode()
        {
            return foo.GetHashCode() ^ bar.GetHashCode();
        }

        public override bool Equals(object obj)
        {
            DataObject that = obj as DataObject;
            return (that != null && this.foo == that.foo && String.Equals(this.bar, that.bar));
        
        }
        public override string ToString(){
            return String.Format("foo : {0}, bar : {1}", this.foo, this.bar);
        }
    }