Types of Design Pattern

Gang of Four (GoF), in their book “Design Patterns: Elements of Reusable Object-Oriented Software”,  catalogued a collection of 23 patterns under 3 categories.  They are,

1. Creational Design Pattern
2. Structural Design Pattern
3. Behavioral design patterns

Creational Design Patterns:

Creational Patterns hide the complexity of creating new object(s) from client code which is going to use these object(s).

Creational Patterns may be used when a decision needs to be taken at the time of object creation.  These patterns automatically restrict the no of objects to be created from a class (Example: Singleton).

When initiating objects using ‘new’ keyword without proper design, may lead to tight coupling of objects.  To resolve these issues, appropriate creational design patterns might be chosen.

The following 6 patterns fall under the category of creational design patterns:

1. Factory Method Pattern
2. Abstract Factory Pattern
3. Singleton Pattern
4. Prototype Pattern
5. Builder Pattern
6. Object Pool Pattern