The builder pattern

We just covered the first two creational patterns, the factory method and the 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.

Real-world examples

In our everyday life, the builder design pattern is used in fast-food restaurants. The same procedure is always used to prepare a burger and the packaging (box and paper bag), even if there are many kinds of burgers (classic, cheeseburger, and more) and different packages...