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What is the point of the Factory pattern?
The stated purpose of the Factory Patterns is: Define an interface for creating an object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses.
Why is class called an object factory explain with two real life examples?
a) A class is called an object factory because objects are created from a class. For example: in real life, a car is an object. The car has attributes, such as weight and color, and methods, such as drive and brake. A Class is like an object constructor, or a “blueprint” for creating objects.
What is known as object factory?
A class is called an object factory because objects are created from a class. An objectis an instance of a class.
How are factories invoked in object oriented programming?
Factories may be invoked in various ways, most often a method call (a factory method ), sometimes by being called as a function if the factory is a function object (a factory function ). In some languages factories are generalizations of constructors, meaning constructors are themselves factories and these are invoked in the same way.
Why do we use factories instead of Constructors?
Using factories instead of constructors or prototypes allows one to use polymorphism for object creation, not only object use.
What’s the difference between a prototype and a factory?
A prototype object is concrete in that it is used to create objects by being cloned, while a factory can create objects by cloning various prototypes, or by other allocation schemes.
How is a factory function implemented in Python?
In Python, a factory function f that instantiates a class A can be implemented as: A simple factory function implementing the singleton pattern is: This will create an object when first called, and always return the same object thereafter.