Overview of Common Software Design Patterns with Humorous Analogies

01. Factory Method

The author compares fast‑food restaurants that produce chicken wings to a Factory Method: the client asks the factory for a product without needing to know how it is created, and new products can be added without changing the client code.

02. Builder

A multilingual translation device with a button for each language is used as a Builder analogy: the construction process is separated from the product’s internal representation, allowing different final products to be built step‑by‑step.

03. Abstract Factory

Ordering a hamburger at a restaurant where the customer specifies the exact type mirrors an Abstract Factory: the core factory delegates creation to concrete factories, exposing only an interface for product creation.

04. Prototype

Collecting pre‑written love messages that can be copied and sent is likened to the Prototype pattern, where new objects are created by cloning an existing prototype.

05. Singleton

The narrator describes being the sole husband of six wives, illustrating the Singleton pattern’s guarantee of a single instance shared across the system.

06. Adapter

A friend acting as a language adapter between the narrator and a Hong‑Kong speaker demonstrates the Adapter pattern, which converts one interface into another expected by the client.

07. Bridge

Using different greetings for various situations (morning, evening, new clothes, new hairstyle) is presented as a Bridge pattern, decoupling abstraction from implementation so they can vary independently.

08. Composite

A birthday gift‑selection scenario where individual items (t‑shirt, dress, bag) are treated as a single composite object exemplifies the Composite pattern’s tree structure for whole‑part relationships.

09. Decorator

Adding a photo, a frame, and a custom box to a gift mirrors the Decorator pattern, which dynamically adds responsibilities to objects without altering their core.

10. Facade

A Nikon camera’s automatic mode that hides complex settings behind a simple interface illustrates the Facade pattern, providing a high‑level entry point to a subsystem.

11. Flyweight

Storing frequently used sentences on a phone and reusing them with a name prefix demonstrates the Flyweight pattern’s sharing of intrinsic state to reduce memory usage.

12. Proxy

Automating replies to common chat greetings with a proxy program shows how a Proxy controls access to the real subject, handling routine requests itself.

13. Chain of Responsibility

Passing a love note through a chain of classmates until someone handles it exemplifies the Chain of Responsibility, where a request traverses a linked list of handlers.

14. Command

Encapsulating a request to a sister’s brother as a command object separates the invoker from the executor, illustrating the Command pattern’s ability to queue, log, and undo operations.

15. Interpreter

Using a script of dating steps as an interpreter to execute actions mirrors the Interpreter pattern, which defines a grammar and evaluates sentences in that language.

16. Iterator

Repeatedly asking a partner for more expensive items (diamond, villa, sports car) and iterating over the list of demands reflects the Iterator pattern’s way of accessing elements of a collection sequentially without exposing its internal structure.

17. Mediator

Settling a Mahjong payment dispute by acting as a neutral mediator shows how the Mediator pattern centralizes complex communications between objects.

18. Memento

Saving conversation snapshots in a notebook to restore later demonstrates the Memento pattern’s ability to capture and restore an object’s internal state without breaking encapsulation.

19. Observer

Subscribing to a company’s intelligence mailing list so updates are pushed automatically illustrates the Observer pattern’s one‑to‑many dependency.

20. State

Changing a partner’s behavior based on her current emotional state exemplifies the State pattern, where an object alters its behavior when its internal state changes.

21. Strategy

Selecting different courting tactics (movie, snack, beach) for different partners shows the Strategy pattern’s encapsulation of interchangeable algorithms.

22. Template Method

Describing a fixed sequence of steps for a romantic encounter (meeting, breaking ice, courting, etc.) with customizable sub‑steps mirrors the Template Method pattern.

23. Visitor

Hiring a florist and a gift‑shop owner to tailor flowers and cards for each partner demonstrates the Visitor pattern, which separates operations from the object structure they act upon.