SOLID & Design Patterns Interview Question #30

What is the Builder Pattern?

Structural, Creational & Behavioral Patterns Junior Beginner

Quick Interview Answer

The Builder Pattern separates the step-by-step construction of a complex object from its final representation. It is useful when an object has many optional values, validation rules, or construction steps.

Detailed Explanation

A builder can make creation code more readable than a constructor with many parameters. It is unnecessary for simple objects that can be constructed clearly with normal constructors or object initializers.

Code Example

var request = new ReportRequestBuilder()
    .ForCustomer(customerId)
    .From(startDate)
    .To(endDate)
    .IncludeDetails()
    .Build();