Builder Pattern in C#: Practical Implementation and Examples

This pattern can be ideal approach to create complex objects

The Builder pattern is a creational design pattern that is used to construct complex objects step by step. It allows you to create different representations of an object using the same construction process.

Let’s first understand the problems that exist without using this pattern.

1. Complex Constructor with Many Parameters

When creating objects that require many parameters, constructors can become lengthy and hard to read.

public class House
{
    public House(int walls, int doors, int windows, bool hasGarage, bool hasSwimmingPool, bool hasStatues, bool hasGarden)
    {
        // Initialization
    }
}

There are many problems if constructor have too many parameters

i) Each time we need to pass n numbers of parameters at time of object creations

ii) we need to update constructor if we need to pass one more parameter so such constructor difficult to manage

1. Constructor Overload Explosion

Sometimes we need to create overloaded constructor based on parameters, so managing multiple constructors again have some headache.

To handle different combinations of parameters, multiple constructor overloads are often created, leading to code duplication and increased maintenance.

public House(int walls, int doors) { ... }
public House(int walls, int doors, int windows) { ... }
public House(int walls, int doors, int windows, bool hasGarage) { ... }

3. Readability and Maintainability Issues:

Code that creates instances with many parameters becomes hard to read and maintain.

var house = new House(4, 2, 6, true, false, true, true);

Introduction of Builder pattern to fix those issues
The Builder pattern breaks down the construction of a complex object into simpler steps. Each step builds a part of the product, and the final step assembles the product.

Builder Pattern
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