Xamarin

public class Dog : RealmObject 
{
    public string Name { get; set; }
    public int Age { get; set; }
}

var realm = Realm.GetInstance();
realm.Write(() => 
{
    var mydog = realm.CreateObject<Dog>();
    mydog.Name = "Rex";
    mydog.Age = 1;
});

var pups = realm.All<Dog>().Where(d => d.Age < 2);