What does it mean to let the subclass decide in the Factory Method pattern?

What does it mean to let the subclass decide in the Factory Method pattern?

The essence of the Factory Pattern is to “Define an interface for creating an object, but let the subclasses decide which class to instantiate. The Factory method lets a class defer instantiation to subclasses.

Why would a factory method design pattern be a more appropriate design than an abstract factory design pattern?

The idea behind the Factory Method pattern is that it allows for the case where a client doesn’t know what concrete classes it will be required to create at runtime, but just wants to get a class that will do the job while Abstract Factory pattern is best utilized when your system has to create multiple families of …

What is the purpose of the factory class in the factory design pattern?

Factory Method Pattern allows the sub-classes to choose the type of objects to create. It promotes the loose-coupling by eliminating the need to bind application-specific classes into the code.

Which Factory Method pattern uses inheritance and relies on a subclass to handle the desired object instantiation?

abstract factory
The factory method is just a method, it can be overridden in a subclass, whereas the abstract factory is an object that has multiple factory methods on it. The Factory Method pattern uses inheritance and relies on a subclass to handle the desired object instantiation.

Which design pattern defines an interface for creating an object but let the subclasses decide which class to instantiate?

The Factory Method defines an interface for creating objects, but lets subclasses decide which classes to instantiate. Injection molding presses demonstrate this pattern. Manufacturers of plastic toys process plastic molding powder, and inject the plastic into molds of the desired shapes.

What do we call the creation of an object for example with the new operator in Java?

Instantiation: The new keyword is a Java operator that creates the object. Initialization: The new operator is followed by a call to a constructor, which initializes the new object.

Why should I use factory class instead of direct object construction?

Case in point, by using “new” and a public constructor, you are coupling the calling code to a specific construction method of a specific concrete class. Your code now has to know that a class MyFooObject exists, and has a constructor that takes a string and an int.

Can a subclass return different types of products?

There’s a slight limitation though: subclasses may return different types of products only if these products have a common base class or interface. Also, the factory method in the base class should have its return type declared as this interface. All products must follow the same interface.

Can you declare the factory method as abstract?

You can declare the factory method as abstract to force all subclasses to implement their own versions of the method. As an alternative, the base factory method can return some default product type. Note, despite its name, product creation is not the primary responsibility of the creator.

Why is the factory method design pattern more useful than having?

Instead, when you don’t use the factory, you would have that code repeatedly used in several locations in your code. As an example consider the following: you need to load data from a DB, but you have one central DB for integration with lots of data, and one smaller one in memory on each dev-PC.