🎯Deeper into Dart

Dart is a rich language with many features. As we delve deeper, we'll cover some key concepts that will help you write more efficient and maintainable Flutter apps.

1. Async/Await and Futures 🕒

Dart has built-in support for asynchronous programming, which is crucial for IO-bound work like loading files or making network requests.

Future<String> fetchUserData() {
  // Simulate a network request
  return Future.delayed(Duration(seconds: 2), () => 'User Data');
}

void getUserData() async {
  String userData = await fetchUserData();
  print(userData);  // Prints: User Data
}

2. Streams 🌊

Streams provide a way to respond to a series of data over time, like user input or a file being read.

Stream<int> countStream(int max) async* {
  for (int i = 1; i <= max; i++) {
    yield i;  // Pauses execution, returns the value, then continues from here when resumed
    await Future.delayed(Duration(seconds: 1));
  }
}

void listenToStream() {
  countStream(5).listen((int value) {
    print(value);  // Prints 1, 2, 3, 4, 5 (each on a new line, once per second)
  });
}

3. Collections (List, Set, Map) 🗂️

Dart has powerful collection types like Lists, Sets, and Maps.

// List
List<String> fruits = ['apple', 'banana', 'cherry'];
fruits.add('date');

// Set
Set<String> colors = {'red', 'green', 'blue'};
colors.add('yellow');

// Map
Map<String, int> ages = {
  'Alice': 30,
  'Bob': 25,
};
ages['Charlie'] = 35;

4. Error Handling 🛑

Handle errors gracefully using try-catch blocks.

void mightFail() {
  throw ('This function throws an error!');
}

void handleError() {
  try {
    mightFail();
  } catch (e) {
    print('Error: $e');
  }
}

5. Custom Classes and OOP 🧩

Leverage Object-Oriented Programming (OOP) principles to create custom classes.

class Person {
  String name;
  int age;

  Person(this.name, this.age);

  void greet() {
    print('Hello, my name is $name and I am $age years old.');
  }
}

void createPerson() {
  Person person = Person('Alice', 30);
  person.greet();  // Prints: Hello, my name is Alice and I am 30 years old.
}

Assignments 📝

Reinforce your learning with these exercises:

• Create a function that returns a Future and use it with async/await.

• Create a Stream and listen to it in another function.

• Implement a custom class with a constructor, method, and properties. Instantiate it and call a method on it.

• Use a try-catch block to handle an error in a function

These topics are fundamental for working effectively with Flutter. By understanding these Dart concepts, you'll be well-equipped to tackle more complex tasks in your Flutter projects.

Up next, delve deeper into & State Management to learn how to create dynamic and responsive user interfaces!