The difference between Builder Design pattern and Factory Design pattern?


What is the difference between the Builder design pattern and the Factory design pattern?

Which one is more advantageous and why ?

How do I represent my findings as a graph if I want to test and compare/contrast these patterns ?

Best Solution

With design patterns, there usually is no "more advantageous" solution that works for all cases. It depends on what you need to implement.

From Wikipedia:

  • Builder focuses on constructing a complex object step by step. Abstract Factory emphasizes a family of product objects (either simple or complex). Builder returns the product as a final step, but as far as the Abstract Factory is concerned, the product gets returned immediately.
  • Builder often builds a Composite.
  • Often, designs start out using Factory Method (less complicated, more customizable, subclasses proliferate) and evolve toward Abstract Factory, Prototype, or Builder (more flexible, more complex) as the designer discovers where more flexibility is needed.
  • Sometimes creational patterns are complementary: Builder can use one of the other patterns to implement which components get built. Abstract Factory, Builder, and Prototype can use Singleton in their implementations.

Wikipedia entry for factory design pattern:

Wikipedia entry for builder design pattern: