Which of the following type of class allows only one object of it to be created?

The type of class that allows only one object of it to be created is known as a singleton class. This design pattern restricts the instantiation of a class to a single instance and provides a global point of access to that instance.

Key Characteristics of Singleton Class:

1. Private Constructor: The constructor is private to prevent the creation of objects from outside the class.
2. Static Instance Method: It provides a static method that returns the instance of the singleton class. This method checks if an instance already exists and creates one if it does not.
3. Global Access Point: It provides a method that can be called from anywhere in the program to access the instance.

Example in Programming:

In languages like Java, a singleton class can be implemented as follows:

public class Singleton {
    private static Singleton instance;

    private Singleton() {
        // private constructor
    }

    public static Singleton getInstance() {
        if (instance == null) {
            instance = new Singleton();
        }
        return instance;
    }
}

This structure ensures that only one instance of Singleton can be created and provides a global access point to that instance.