How do standard and named constructors differ in programming languages?

In programming languages like Dart (used in Flutter), standard constructors are basic class constructors that create an object with a specific set of parameters.

Named constructors are additional constructors with unique names, allowing objects to be created in different ways, improving readability and usability.

Example in Dart:

class User {
  String name;
  int age;

  User(this.name, this.age); // standard constructor

  User.guest() {
    name = 'Guest';
    age = 0;
  } // named constructor
}

void main() {
  var user1 = User('Alice', 30);
  var user2 = User.guest();
}

Named constructors help create objects with different initial states.