marcel-ploch

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,

marcel-ploch

class MeinSingleton {
  /// Unsere Singleton Instanz, die einmalig instanziiert wird
  static final MeinSingleton _singleton = MeinSingleton._internal();
  
  /// Member Variable, die zugreifbar gemacht werden soll
  late List<dynamic> data = [];

  /// Factory Constructor, der die Instanz der Klasse zurückgibt, egal wann sie aufgerufen wird
  factory MeinSingleton() {
    return _singleton;

marcel-ploch

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override

marcel-ploch

class MeinObjektPositionsParameter {
  String name = "";
  // Positions Parameter an Stelle 1
  MeinObjektPositionsParameter(this.name);
}

class MeinObjektOptionalParameterDefault {
  String name = "";
  // Positions Parameter an Stelle 1, aber optional mit default value
  MeinObjektOptionalParameterDefault([this.name = 'FOO']) ;

marcel-ploch

class User {
  String name;
  String type;
  User({required this.name, required this.type});
}


enum MyEnum {
  foo("test", "admin"),
  bar("test2", "user");

marcel-ploch

Future<int> sumStream(Stream<int> stream) async {
  var sum = 0;
  await for (final value in stream) {
    sum += value;
  }
  return sum;
}

Stream<int> countStream(int to) async* {
  for (int i = 1; i <= to; i++) {

marcel-ploch

import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:math';

void main() {
  runApp(const MyApp());
}

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

marcel-ploch

// Erweitere die Klasse string um die NumberParsing Extension
extension StringParsing on String {
  String changeDirection() {
    return this.split('').reversed.join();
  }
  // ···
}

class Person {
  String name = '';

marcel-ploch

Future<void> printOrderMessage() async {
  print('Awaiting user order...');
  var order = await fetchUserOrder();
  print('Your order is: $order');
}
Future<String> fetchUserOrder() {
  // Imagine that this function is more complex and slow.
  return Future.delayed(const Duration(seconds: 4), () => 'Large Latte');
}
void main() async {

marcel-ploch

add2Numbers(int number1, {required int number2}) {
 return number1 + number2;
}

add2NumbersNotReq([int number1 = 5, int number2 = 10]) {
 return number1 + number2;
}

add2NumbersNamedOptional({required int number1, int? number2}) {
  return number1 + (number2 ?? 0);