Classes

A 128-bit IEEE 754-2008 decimal floating point number.

This type is similar to Swift’s built-in Decimal type, but allocates bits differently, resulting in a different representable range. (NS)Decimal stores a significand of up to 38 digits long and an exponent from -128 to 127, while this type stores up to 34 digits of significand and an exponent from -6143 to 6144.

A 12-byte (probably) unique object identifier.

ObjectIds are similar to a GUID or a UUID, and can be used to uniquely identify objects without a centralized ID generator. An ObjectID consists of:

1. A 4 byte timestamp measuring the creation time of the ObjectId in seconds since the Unix epoch.
2. A 5 byte random value
3. A 3 byte counter, initialized to a random value.

ObjectIds are intended to be fast to generate. Sorting by an ObjectId field will typically result in the objects being sorted in creation order.

List is the container type in Realm used to define to-many relationships.

Like Swift’s Array, List is a generic type that is parameterized on the type it stores. This can be either an Object subclass or one of the following types: Bool, Int, Int8, Int16, Int32, Int64, Float, Double, String, Data, Date, Decimal128, and ObjectId (and their optional versions)

Unlike Swift’s native collections, Lists are reference types, and are only immutable if the Realm that manages them is opened as read-only.

Lists can be filtered and sorted with the same predicates as Results<Element>.

Properties of List type defined on Object subclasses must be declared as let and cannot be dynamic.

A RealmOptional instance represents an optional value for types that can’t be directly declared as @objc in Swift, such as Int, Float, Double, and Bool.

To change the underlying value stored by a RealmOptional instance, mutate the instance’s value property.