What is the Singleton pattern?

A singleton is a creational design pattern that guarantees that only one instance of a class exists at any given time and provides a global point of access to it. It is used for centralized management of resources or configurations.

Example implementation in Swift:

class Singleton {
    static let shared = Singleton() // Static property for the single instance

    private init() { // Private initializer prevents creating new instances from outside
        // Singleton setup
    }

    func someMethod() {
        // Singleton logic
    }
}

// Using singleton
let instance = Singleton.shared
instance.someMethod()