What is the difference between Builder Design patt

Question

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 ?

Answer 1

+-------------------------------------------------------------------+---------------------------------------------------+
|                              Builder                              |                      Factory                      |
+-------------------------------------------------------------------+---------------------------------------------------+
| Return only single instance to handle complex object construction | Retrun various instances on multiple constructors |
| No interface required                                             | Interface driven                                  |
| Inner classes is involved (to avoid telescopic constructors)      | Subclasses are involved                           |
+-------------------------------------------------------------------+---------------------------------------------------+  

Telescoping Constructor Pattern

Analogy:

• Factory: Consider a restaurant. The creation of "today's meal" is a factory pattern, because you tell the kitchen "get me today's meal" and the kitchen (factory) decides what object to generate, based on hidden criteria.
• Builder: The builder appears if you order a custom pizza. In this case, the waiter tells the chef (builder) "I need a pizza; add cheese, onions and bacon to it!" Thus, the builder exposes the attributes the generated object should have, but hides how to set them.

Courtesy

Answer 2

Both are very much similar , but if you have a large number of parameters for object creation with some of them optional with some default values , go for Builder pattern.

Answer 3

The Factory pattern can almost be seen as a simplified version of the Builder pattern.

In the Factory pattern, the factory is in charge of creating various subtypes of an object depending on the needs.

The user of a factory method doesn't need to know the exact subtype of that object. An example of a factory method createCar might return a Ford or a Honda typed object.

In the Builder pattern, different subtypes are also created by a builder method, but the composition of the objects might differ within the same subclass.

To continue the car example you might have a createCar builder method which creates a Honda-typed object with a 4 cylinder engine, or a Honda-typed object with 6 cylinders. The builder pattern allows for this finer granularity.

Diagrams of both the Builder pattern and the Factory method pattern are available on Wikipedia.

Answer 4

Both are Creational patterns, to create Object.

1) Factory Pattern - Assume, you have one super class and N number of sub classes. The object is created depends on which parameter/value is passed.

2) Builder pattern - to create complex object.

Ex: Make a Loan Object. Loan could be house loan, car loan ,
    education loan ..etc. Each loan will have different interest rate, amount ,  
    duration ...etc. Finally a complex object created through step by step process.

Answer 5

Build pattern emphasizes on complexity of creating object (solved by "steps")

Abstract pattern emphasizes "just" on "abstraction" of (multiple but related) objects.

Answer 6

Difference is clear In builder pattern, builder will create specific type of object for you. You have to tell what builder has to build. In factory pattern , using abstract class you are directly building the specific object.

Here builder class acts as mediator between main class and specific type classes. More abstraction.