Creational Design Patterns

Creational Design Patterns focus on the process of object creation or problems related to object creation. They help in making a system independent of how its objects are created, composed, and represented. Creational patterns give a lot of flexibility in what gets created, who creates it, and how it gets created. There are two main themes in these patterns:

• They keep information about the specific classes used in the system hidden.
• They hide the details of how instances of these classes are created and assembled.

Types of Creational Design Patterns

There are mainly 5 types of creational design patterns:

1. Factory Method Design Patterns
2. Abstract Factory Method Design Patterns
3. Singleton Method Design Pattern
4. Prototype Method Design Patterns
5. Builder Method Design Patterns

Sometimes creational patterns are competitors. For Example: there are cases when either Prototype or Abstract Factory could be used profitably. At other times they are complimentary: Builder can use one of the other patterns to implement which components get built. The Prototype can use Singleton in its implementation.

1. Factory Method Design Pattern

This pattern is typically helpful when it’s necessary to separate the construction of an object from its implementation. With the use of this design pattern, objects can be produced without having to define the exact class of object to be created. Below is when to use Factory Method Design Pattern:

• A class can't anticipate the class of objects it must create.
• A class wants its subclass to specify the objects it creates.
• Classes delegate responsibility to one of several helper subclasses, and you want to localize the knowledge of which helper subclass is the delegate.

2. Abstract Factory Method Design Pattern

Abstract Factory pattern is almost similar to Factory Pattern and is considered as another layer of abstraction over factory pattern. Abstract Factory patterns work around a super-factory which creates other factories. Below is when to use Abstract Factory Method Design Pattern:

• A system should be independent of how its products are created, composed, and represented.
• A system should be configured with one of multiple families of products.
• A family of related product objects is designed to be used together, and you need to enforce this constraint.
• You want to provide a class library of products, and you want to reveal just their interfaces, not their implementations.

3. Singleton Method Design Pattern

The Singleton method or Singleton Design pattern is one of the simplest design patterns. It ensures a class only has one instance, and provides a global point of access to it. Below is when to use Singleton Method:

• There must be exactly one instance of a class, and it must be accessible to clients from a well-known access point.
• When the sole instance should be extensible by subclassing, and clients should be able to use an extended instance without modifying their code.

4. Prototype Method Design Pattern

Prototype allows us to hide the complexity of making new instances from the client. The concept is to copy an existing object rather than creating a new instance from scratch, something that may include costly operations. Below is when to use Prototype Method:

• Use the Prototype pattern when a system should be independent of how its products are created, composed, and represented; and
• When the classes to instantiate are specified at run-time, for example, by dynamic loading.
• To avoid building a class hierarchy offactories that parallels the class hierarchy of products.

5. Builder Method Design Pattern

Builder Design Pattern is used to Separate the construction of a complex object from its representation so that the same construction process can create different representations. It helps in constructing a complex object step by step and the final step will return the object. Use It when:

• The algorithm for creating a complex object should be independent of the parts that make up the object and how they're assembled.
• The construction process must allow different representations for the object that's constructed.

Benefits of Creational Design Patterns

Creational design patterns offer several key benefits:

• They allow for greater flexibility in object creation. By decoupling the process of instantiation from the rest of the system, you can easily change the class being instantiated without affecting other components.
• These patterns encapsulate the logic of object creation, which simplifies code management and promotes cleaner, more organized code.
• By centralizing the creation logic, these patterns promote reusability. You can use the same creation methods across different parts of the application.
• They help manage complex object creation processes, making it easier to handle configurations and dependencies, especially when dealing with many related classes.