dart -2

9. List

java 비슷

bool isDone = true;

List items = [1,2,3, if(isDone) 99];

items.first();
items.last();
items.isEmpty();
items.length;

for(int item in items) {}

List addItem = [...items, 4, 5,6]; // spread 연산자

10. Map
    Map<String, dynamic> men = {
    'name' : 'john',
    'age' : 40
    };

    men('name') = 'kitty'; // update

    print(men.keys); // name, age
    print(men.entries);
    print(men.values);

    for( var key in men.keys) {
    print(men[key]);
    }

    for(var entry in men.entreis) {
    print('${entiry.key}, ${entiry.value}');
    }

11. class

    void main() {

    var point1 = Point(1, 2);
    point1.move();
    print(point1.x);
    porint1.y = 100;
    print(Point.glovalName); // static 이므로
    Point.glovalName = 'yourName';

    Point point3 = Point.fromMap({ 'x':10, 'y':20});

    }

    String newGlovalText = 'allRound'; // 어디에서든 쓸 수 있어서
    // static보다 편리함

    class Point {
    int x=0;
    int y=0;
    int z=0; // 붙이면 private가 됨
    int? t;
    late int s; // late 지연 초기화

    static String glovalName ='myName;

    Point(this.x; this.y, this._z, [this.t]); // t를 넣어도 되고 안넣어도 됨

    void move() {
    	print('move');
    }

    static void test() {
    print('test');
    }

    // named constructor 

    Point.fromMap(Map map) {
    _x = map['x'];
    _y = map['y'];
    }
    }

12. 상속

    자바와 비슷

13. mixin : 다중상속

    void main() {

    }

    mixin Moveable {
    int i=0;

    }

    SuperHero sh extends Hero with Moveable ...

14. generic

    class Box {
    T value;
    }

    void main() {
    var box = Box(11);
    var box2 = Box('strbox');
    }

15. import

    import 'dart:async' as async;

    import 'dart:async' hide AsyncError;
    import 'dart':aync' show AsyncError;

16. Future : 비동기 처리

    var delay = Future.delayed(Duration(seconds:3));
    delay.then((value) => print('3seconds delay')
    .catchError((e) => print(e));
    delay.whenComplete(...)

    Future hello() async {
    await Fure.delayed(Duration(seconds:3));
    return 'hello';
    }

    hello.then((value) => print(value));

17. stream : data 흐름

    var stream =STream.fromIterable([1,2,3]);

    stream.listen((event) {
    print(event);
    });