What is the Builder Pattern?
Updated Apr 28, 2026
Short answer
A creational pattern that lets you construct complex objects step by step.
Deep explanation
Builder extracts the object construction code out of its own class and moves it to separate objects called builders. It prevents the 'Telescoping Constructor' anti-pattern (constructors with dozens of optional parameters) and allows for fluent interfaces.
Real-world example
Constructing a complex SQL query string where clauses (SELECT, WHERE, ORDER BY) are added conditionally step-by-step.
Common mistakes
- Using a Builder for simple objects that only require a few constructor arguments.
Follow-up questions
- What is the role of the Director in the Builder pattern?