Creational Design Pattern: Builder Pattern

Define Builder Pattern

The builder pattern creates a complex object step by step. The Builder interface specifies the steps required to create the final item. This builder operates independently of the object's creation process. The process of creating objects is controlled by a class called Director. Furthermore, the builder pattern explains how to isolate an object from its creation. The same creation approach can result in distinct representations of the object.

Builder Design pattern with UML diagram

The UML class diagram above defines the following classes, interfaces, and objects:

1. Builder: This interface defines all the stages required to develop a product.
2. ConcreteBuilder: This class uses the Builder interface to produce a complicated product.
3. Product: This class defines the complicated object components that will be created using the builder pattern.
4. Director: This class creates an object via the Builder interface.

When to use the Builder pattern?

The builder pattern is useful in the following situations:

• An item must be created in a series of steps.
• Objects should be created independently of how their parts are assembled.
• Runtime control of the creation process is required.

Why use the Builder Pattern?

• Parameters Overload: Allows you to avoid large lists of parameters in constructors.
• Immutability: Allows you to create immutable objects.
• Readability: Creates clean and readable objects.