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What is the factory method patterns explain with examples?
Example. 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 type of pattern is the factory pattern?
In class-based programming, the factory method pattern is a creational pattern that uses factory methods to deal with the problem of creating objects without having to specify the exact class of the object that will be created.
What is the use of factory design pattern?
The factory design pattern says that define an interface ( A java interface or an abstract class) and let the subclasses decide which object to instantiate. The factory method in the interface lets a class defer the instantiation to one or more concrete subclasses.
What is the purpose of 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.
What is the purpose of factory design pattern?
What’s the point of factory pattern?
Why is factory pattern bad?
That’s just a bad habit. The Factory Method is a design pattern that relies on inheritance. If you make it static , you can no longer extend it in subclasses, which defeats the purpose of the pattern. When a static creation method returns new objects it becomes an alternative constructor.
Is factory method a design pattern?
Factory Method is a creational design pattern that provides an interface for creating objects in a superclass, but allows subclasses to alter the type of objects that will be created.
What is disadvantage of factory pattern?
One disadvantage of the Factory Method pattern is that it can expand the total number of classes in a system. Every concrete Product class also requires a concrete Creator class. The parameterized Factory Method avoids this downside.
Why is the factory method a design pattern?
The factory method in the interface lets a class defer the instantiation to one or more concrete subclasses. Since this design patterns talk about instantiation of an object and so it comes under the category of creational design pattern.
Is there a simple factory pattern in Java?
The first time I read this pattern, I misinterpreted it with the static one which was described by Joshua Bloch – one of the main architects of the Java APIs – in his book “Effective Java “. The simple factory (sometimes called factory) is informal but appears many times on the net.
Which is the best design pattern to create an object?
This type of design pattern comes under creational pattern as this pattern provides one of the best ways to create an object. In Factory pattern, we create object without exposing the creation logic to the client and refer to newly created object using a common interface.
Do you use a factory to create a simpleclass?
In this code, SimpleClass is a very simple class with a state, no dependencies, no polymorphism and no business logic. You could use a factory to create this object but it would double the amount of code. Therefore, it would make the code more difficult to understand. If you can avoid using factories do it, you’ll end up with simpler a code!