default cuntion on construct dart code example

Example 1: dart call constructor in constructor

class Chipmunk {
  String name;
  int fame;

  Chipmunk.named(this.name, [this.fame]);

  Chipmunk.famous1() : this.named('Chip', 1000);
  factory Chipmunk.famous2() {
    var result = new Chipmunk.named('Chip');
    result.fame = 1000;
    return result;
  }
}

Example 2: flutter constructor default value

class Customer {
  String name;
  int age;
  String location;

  Customer(this.name, [this.age, this.location = "US"]);

  @override
  String toString() {
    return "Customer [name=${this.name},age=${this.age},location=${this.location}]";
  }
}