Can you explain the Singleton concept and its application in programming?

Singleton is a design pattern that guarantees a class has only one instance and provides a global point of access to it.

Application:

• When you need to control access to a resource (e.g., a database, application settings).
• To manage a state that should be consistent throughout the application.

Example in Swift:

class Singleton {
    static let shared = Singleton()
    private init() { }

    func doSomething() {
        print("Performing an action")
    }
}

// Usage
Singleton.shared.doSomething()

Here, shared is the only instance of the class, and the init constructor is private to prevent creating other objects.