Creational Design Patterns

Creational design patterns deal with object creation mechanisms, trying to create objects in a manner suitable to the situation. They help make a system independent of how its objects are created, composed, and represented.

These patterns abstract the instantiation process, making it more flexible and reusable.

Purpose

• Reduce complexity in object creation
• Promote loose coupling
• Increase flexibility and reusability
• Hide instantiation logic

List of Main Creational Design Patterns

1. Singleton Pattern
   Ensures a class has only one instance and provides a global point of access to it.

   • Useful for: Logging, configuration, database connections
   • Key concepts: Private constructor, static instance, thread safety

2. Factory Method Pattern
   Defines an interface for creating objects, but lets subclasses alter the type of objects that will be created.

   • Useful for: Delegating object creation to subclasses
   • Key concepts: Inheritance, interface-based creation

3. Builder Pattern
   Separates the construction of a complex object from its representation so that the same construction process can create different representations.

   • Useful for: Building objects with many optional parameters
   • Key concepts: Step-by-step construction, fluent interface

4. Prototype Pattern
   Creates new objects by copying an existing object (clone), rather than creating from scratch.

   • Useful for: Performance-intensive object creation
   • Key concepts: Cloning, deep vs. shallow copy

5. Abstract Factory Pattern
   Provides an interface for creating families of related objects without specifying their concrete classes.

   • Useful for: UI components across platforms (Windows/Mac/Linux)
   • Key concepts: Factory of factories, product families

Summary Table