This code creates a Singleton class with a private constructor and a getInstance method that returns the same instance of the class if it has already been created, or creates a new one if not.
Example 2:This code creates a Database class with a private constructor that takes in host, username, password, and database parameters for a connection. The getInstance method creates and returns the same instance of the class if it has already been created, or creates a new one with the specified connection parameters if not. This code belongs to the PHP Core package/library as it is a core concept of Object-Oriented Programming and can be used in any PHP program regardless of the package/library being used.