Dart Foundations

Flutter is Dart

Before a single widget, we start with the language, because every line of Flutter you write is Dart. The framework’s shape — immutable widgets, const constructors, async/await in your build logic, mixins like SingleTickerProviderStateMixin — is a direct consequence of Dart’s features. Learn the language well and Flutter stops being a pile of magic incantations.

What this module covers

Lesson	What you’ll learn
Dart language tour	Types, variables, functions, collections — the essentials, fast
Null safety	Sound null safety, the operators, and flow analysis
Classes & mixins	Constructors (named/factory/const), mixins, extensions, enums
Async in Dart	Future, async/await, Stream, and the single-threaded event loop

Why these four, specifically

These aren’t a random language tour — each one shows up constantly in Flutter code:

flowchart LR
  ns["Null safety"] --> w["safe widget props,
optional params"]
  cc["const constructors"] --> perf["cheap widget rebuilds"]
  mx["mixins"] --> st["State mixins
(tickers, observers)"]
  as["async / Stream"] --> ui["FutureBuilder,
StreamBuilder"]

How each Dart feature powers Flutter

Null safety decides how you model optional widget properties and data.
const constructors are the single biggest lever for Flutter performance — a const widget is skipped on rebuild.
Mixins are how Flutter adds capabilities to your State classes.
Async and Streams are how your UI talks to the network, databases, and time.