Revision Notes/Design Patterns
Field Entry - Design Patterns
Builder Pattern
Separates the construction of a complex object from its representation, letting you build objects step by step.
Field Note - Real-world Analogy
“Building a custom PC: you go to a configurator and select your CPU, RAM, storage, and GPU one by one. Each selection is like a builder method call. Finally you click "Build" and get your configured machine. You don't have to fill in everything at once in a confusing form.”
Field Observations - Key Topics Covered
The problem: some objects are complex and need many configuration options — like a Pizza with crust type, size, sauce, toppings, extra cheese, etc. If you put all this in a constructor you end up with a method that takes 10 parameters. Half of them are optional and callers have to pass null or undefined for everything they don't want, which is very error-prone.
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