flutter-dart-style

Topics in the source

• Modern Dart & Flutter code style
• 1. Classes & models
• 2. Null safety & control flow
• 3. Widgets
• 4. Naming & structure (Effective Dart)
• 5. Errors & logging
• 6. Lints & tooling (set up once, then trust them)
• 7. Deprecated APIs

Verified 2026-09-25: Flutter 3.47.5 / Dart 3.13.4 (stable). Language features depend on the package's SDK constraint. Check environment: sdk: in pubspec.yaml before using a feature. The minimum language version is noted on each item below. Goal: less code, same behavior, and mistakes caught by the compiler instead of at runtime. Don't write code the SDK, the language, or an existing dependency already provides. Primary constructors (3.13) declare fields and constructor in the header: Widgets too (compile-checked): var/final in the header creates a field. Without it, the parameter is just a parameter. Since 3.13, final/var on ordinary function parameters is a compile error. Concise constructors (3.13) in class bodies: new(this.x, this.y);, new origin() : x = 0, y = 0;, factory fromJson(Map j) => ...;, const new();. Private named parameters (3.12): Point({required this.x}) is called as Point(x: 1). Before 3.13, the equivalent is const Point({required this.x, required this.y}); final int x; final int y;. Immutable by default: final fields, const constructors, copyWith via codegen (freezed/dartmappable) only when you need it. Sealed hierarchies for states/results/events. switch is exha

This is an excerpt. Refer to the complete source and its current requirements.