C# Serialize object via System.Text.Json

using System.Text.Json;

static void TextJsonDemo()
        {
            var obj = new
            {
                Id = 1,
                Name = "Fred",
                Age = 33,
                Org = new[]
                {
                    new
                    {
                        Id=1,
                        Name="MS"
                    },
                    new
                    {
                        Id=2,
                        Name="SMF"
                    },
                    new
                    {
                        Id=3,
                        Name="Agile"
                    }
                }
            };

            string jsonValue = JsonSerializer.Serialize(obj);
            Console.WriteLine(jsonValue);
        }