Why there is a colon symbol (:) with the class constructor in Dart?

Question

I am new in Dart(OOP Languange) which it is a bit similar in Java

But this code get me confusion

What is the purpose of colon(:) before the super keyword within SchoolID class that has been inherit with Person class? Here is the code:

class Person {
  String name;
  int age;
  int height;

  Person({this.name, this.age, this.height});
}

class SchoolID extends Person {
  int id;
  int year;

  String name;
  SchoolID({this.id, this.year, this.name}) : super(name: name);
}

Another Example ,,, focus on colon the fishmap

AllFish.fromJson(Map<String, dynamic> json)
      : fishMap = json.map(
          (String k, dynamic v) => MapEntry(
            k,
            Fish.fromJson(v),
          ),
        );

Answer 1

It's considered as an initializer list which runs before the constructor body, here you're calling the super that means the constructor of your Person class.