Can you explain the concept of the Builder design pattern and its advantages?

The Builder design pattern is used for step-by-step creation of complex objects. It separates the construction process of an object from its representation, allowing different variations of the object to be created using the same process.

Advantages:

• Allows creating objects with many parameters, avoiding constructors with a large number of arguments.
• Improves code readability and maintainability.
• Enables creating different representations of an object using the same construction code.

Example in Dart (Flutter):

class Pizza {
  final String dough;
  final String sauce;
  final String topping;

  Pizza._builder(PizzaBuilder builder)
      : dough = builder.dough,
        sauce = builder.sauce,
        topping = builder.topping;
}

class PizzaBuilder {
  String dough = '';
  String sauce = '';
  String topping = '';

  PizzaBuilder setDough(String dough) {
    this.dough = dough;
    return this;
  }

  PizzaBuilder setSauce(String sauce) {
    this.sauce = sauce;
    return this;
  }

  PizzaBuilder setTopping(String topping) {
    this.topping = topping;
    return this;
  }

  Pizza build() {
    return Pizza._builder(this);
  }
}

void main() {
  var pizza = PizzaBuilder()
      .setDough('Thin crust')
      .setSauce('Tomato')
      .setTopping('Cheese')
      .build();
}