Builder design pattern

The Builder design pattern is a creational design pattern that allows for the step-by-step construction of complex objects. It separates the construction of an object from its representation, so that the same construction process can create different representations. This pattern is often used to create immutable objects, as it ensures that the object is in a valid state before it is returned.

Note📝:

• Construction: In above defination construction, is the process of assembling and configuring the internal components of an object.
• Representation: In above defination representation, is the way those internal components are organized and structured to form the final object.

key points of the Builder Design Pattern:

1. Intent:

   • The main intent of the Builder pattern is to separate the construction of a complex object from its representation so that the same construction process can create different representations.

2. Key Components:

   • Director:
     • Defines the interface for constructing products using the builder.
   • Builder:
     • Declares the interface for constructing parts of the product. It is responsible for building the individual components of the complex object.
   • ConcreteBuilder:
     • Implements the Builder interface to construct and assemble parts of the product. It defines specific methods for building and retrieving the product.
   • Product:
     • Represents the complex object that is being constructed. It typically has a complex structure composed of various parts.

3. Construction Process:

   • The Director class orchestrates the construction process using a Builder interface. It guides the order in which the builder constructs the parts to create the final product.

4. Variability in Representations:

   • The Builder pattern allows for the creation of different representations of the product by using different concrete builders. The same director can be used with different builders to create different products.

5. Step-by-Step Construction:

   • The construction of the product occurs in a step-by-step manner, with the builder adding individual components to the product over successive calls.

6. Fluent Interface (Optional):

   • Builders can be designed to provide a fluent interface, allowing method chaining for a more expressive and readable construction process.

7. Advantages:

   • Separation of Concerns: It separates the construction of a complex object from its representation, allowing for a clear distinction between the construction process and the final product.
   • Flexibility: It allows for the creation of different representations of a product using the same construction process.
   • Encapsulation: The construction details are encapsulated within the builder, preventing the client from having detailed knowledge of the construction process.

8. Use Cases:

   • The Builder pattern is useful when the construction of a complex object involves multiple steps and variations, and the construction process needs to be independent of the final product.
   • It is applicable when an object needs to be constructed with a variety of configurations, and it is more convenient to delegate the construction to a separate builder.