Builder

The builder pattern is a design pattern designed to provide a flexible solution to various object creation problems in object-oriented programming.

The intent of the Builder design pattern is to separate the construction of a complex object from its representation. By doing so, the same construction process can create different representations.

Overview

The Builder design pattern solves problems like:

• How can a class create different representations of a complex object?
• How can a class that includes creating a complex object be simplified?

Creating and assembling the parts of a complex object directly within a class is inflexible. It commits the class to creating a particular representation of the complex object and makes it impossible to change the representation later independently from (without having to change) the class.

The Builder design pattern describes how to solve such problems:

• Encapsulate creating and assembling the parts of a complex object in a separate Builder object.
• A class delegates object creation to a Builder object instead of creating the objects directly.

A class can delegate to different Builder objects to create different representations of a complex object.