diandian82的专栏

mixin Musical { bool canPlayPiano = false; bool canCompose = false; bool canConduct = false; void entertainMe() { if (canPlayPiano) { print('Playing piano'); } else if (canCond...

import 'dart:async';Future<int> sumStream(Stream<int> stream) async{ var sum=0; await for(var value in stream){ sum += value; } return sum;}Stream<int> countStream(...

import 'dart:async';main(List<String> args) async { await for (int i in numbersDownFrom(10)) { print('$i apples'); }}Stream numbersDownFrom(int n) async* { if (n >= 0) { a...

// dart singletonmain(List<String> args) { var helper = DBHelper(); helper = DBHelper(); helper = DBHelper(); helper = DBHelper(); helper = DBHelper(); helper = DBHelper(); hel...

class Point { num x, y; Point(); // Named constructor Point.origin() { x = 1; y = 2; } @override String toString() { // TODO: implement toString return 'x=$x, y=$y';...