[Flutter] Dart 문법 (상속)

* 상속 class Spacecraft { String? name; DateTime?

launchDate; //Constructor, with syntactic sugar for assignment to members. Spacecraft(this.name, this.launchDate) { //Initialization code goes here. } Spacecraft.origin() { name = "무탈리스크"; launchDate = DateTime.now(); } //Named contructor that forwards to the default one.

Spacecraft.unlaunched(String name) : this(name, null); int? get launchYear =>.....