Dart Fundamentals

7 sections to master Dart before (or alongside) Flutter, each with interactive demos

🎯 The foundation before Flutter

Flutter is written in Dart, so these examples are the perfect lead-in to your Flutter section. Each page includes a live form: change the values and see how the real Dart code would respond, with a line-by-line explanation.

📚 Available Sections

🔤

1. Variables and Null Safety

var, final, const, and the operators ?, !, ??, ??= expression in Dart.

null safety types

🔁

2. Control Flow

for classic, for-in, while and the switch expression in Dart 3.

for switch

📋

3. Collections

List, Map, Set and the methods map(), where(), reduce(), fold().

List Map

➡️

4. Functions

Named/optional parameters, arrow functions and closures.

closures arrow fn

🌊

5. Async and Streams

Future, async/await and Streams — the real execution order.

Future Stream

🐾

6. POO in Dart

Classes, named constructors, factory constructors, mixins and inheritance.

mixins inheritance

📦

7. Extras (Dart 3)

Enhanced enums, extension methods and records/patterns.

enums records

💡 How to get the most out of it

🧪 Change the values

Each demo has a form: try edge cases (empty lists, negative numbers, empty text) to see how the code reacts.

📖 Read the explanation

Below each demo there's a breakdown of why the Dart code is written that way, with comparisons to other languages when relevant.

💪 Do the exercise

Each page ends with a challenge to extend the code, with hidden solutions in case you get stuck.