catalunha

import 'dart:math';

void main() {
  NumberQ num1 = NumberQ(
    signal: NumberQSignal.positive,
    integer: 1,
    fractionNum: 2,
    fractionDen: 3,
  );
  NumberQ num2 = NumberQ(

catalunha

import 'dart:math';

Stream<int> getStream(int n) async* {
  if (n > 0) {
    await Future.delayed(Duration(seconds: 1));
    yield n;
    yield* getStream(n - 1);
  }
}

catalunha

void main() async {
  print('aaa');
  Stream<int> stream = countStream(10);
  print('bbb');
  int sum = await sumStream(stream);
  print('ccc');
  print(sum);
}

Stream<int> countStream(int max) async* {

catalunha

void main() {
  for (int i = 0; i < 5; i++) {
    print('hello ${i + 1}');
  }
}

catalunha

import 'dart:async';
import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'package:pdf/widgets.dart' as pw;
import 'package:printing/printing.dart';

class UserProfilePrintPage extends StatelessWidget {
  const UserProfilePrintPage({Key? key}) : super(key: key);

catalunha

class UsingSingleton {
  // using a factory is important
  // because it promises to return _an_ object of this type
  // but it doesn't promise to make a new one.
  factory UsingSingleton() {
    print('... factory UsingSingleton()');
    return _instance;
  }
  static final UsingSingleton _instance = UsingSingleton._internal();
  // This named constructor is the "real" constructor

catalunha

void main() {
  var myClass = MyClass();
  myClass.doSomething1(1);
  myClass.doSomething2(printAnyThing1);
  myClass.doSomething3((value) {
    print('print $value');
  });
    myClass.doSomething4((value) {
    print('print $value');
      return 2;

catalunha

void main() {
  String valorDoSaque = '9';
  sacar(valorDoSaque);
}

void sacar(String valorDoSaque) {
  if (int.parse(valorDoSaque) > 0 && int.parse(valorDoSaque) < 1000) {
    var notas = valorEmNotas(valorDoSaque);
    var texto = valorEmTexto(valorDoSaque);
    if (notas == null) {

catalunha

abstract class Item {
  String name();
  Packing packing();
  double price();
}

abstract class Packing {
  String pack();
}

catalunha

enum ShapeType { circle, square }

abstract class Shape {
  factory Shape(ShapeType type) {
    switch (type) {
      case ShapeType.circle:
        return Circle();
      case ShapeType.square:
        return Square();
    }