Creational patterns are design patterns that deal with how an object is created. These patterns create objects in a manner suitable for a particular situation.
There are two basic ideas behind creational patterns. The first is encapsulating the knowledge of which concrete types should be created and the second is hiding how the instances of these types are created.
There are five well-known patterns that are a part of the creational pattern category. They are as follows:
- Abstract factory pattern: This provides an interface for creating related objects without specifying the concrete type
- Builder pattern: This separates the construction of a complex object from its representation, so the same process can be used to create similar types
- Factory method pattern: This creates objects without exposing the underlying logic of how the object (or which type of object) is created
- Prototype pattern: This creates an object by cloning an existing one
- Singleton pattern: This allows one (and only one) instance of a class for the lifetime of an applications
In this chapter, we are going to show examples of how to implement the singleton and builder patterns in Swift. Let's start off by looking at one of the most controversial and possibly overused design patterns, the singleton pattern.