In the previous chapter, we covered the first two creational patterns, the factory method and abstract factory, which both offer approaches to improve the way we create objects in nontrivial cases.
Now, imagine that we want to create an object that is composed of multiple parts and the composition needs to be done step by step. The object is not complete unless all its parts are fully created. That's where the builder design pattern can help us. The builder pattern separates the construction of a complex object from its representation. By keeping the construction separate from the representation, the same construction can be used to create several different representations (j.mp/builderpat).
A practical example can help us understand what the purpose of the builder pattern is. Suppose that we want to create an HTML page generator. The basic structure ...
