What is the purpose of the singleton pattern in object-oriented programming?

The singleton pattern serves a specific purpose in object-oriented programming by ensuring that a class has only one instance throughout the application and provides a global point of access to that instance. This is particularly useful in scenarios where a single instance is needed to coordinate actions across the system, such as in controlling shared resources like database connections, logging mechanisms, configuration settings, or controlling state within an application.

By restricting the instantiation of a class to a single instance, the singleton pattern helps maintain consistency and manage resources effectively, since it prevents the creation of multiple instances that could lead to conflicting states or excessive resource usage. The pattern usually involves a private constructor to prevent direct instantiation and a static method that provides the access point for obtaining the instance.

This design promotes better management of shared data and reduces overhead associated with creating multiple objects of the same class, thus enhancing performance and maintaining clear control over shared resources.