Welcome to the [Dart](https://dart.dev/) API reference documentation, covering the [Dart core libraries](https://dart.dev/guides/libraries). These include: * [dart:core](dart-core/dart-core-library.html): Core functionality such as strings, numbers, collections, errors, dates, and URIs. * [dart:html](dart-html/dart-html-library.html): DOM manipulation for web apps (available only to web apps). * [dart:io](dart-io/dart-io-library.html): I/O for non-web apps. Except for `dart:core`, you must import a library before you can use it. Here's an example of importing `dart:async` and `dart:math`: ```dart import 'dart:async'; import 'dart:math'; ``` You can find more libraries using the [pub.dev site](https://pub.dev). The main site for learning and using Dart is [dart.dev](https://dart.dev). Check out these pages: * [Platforms](https://dart.dev/platforms) * [Language tour](https://dart.dev/guides/language/language-tour) * [Library tour](https://dart.dev/guides/libraries/library-tour) * [Sample code](https://dart.dev/samples) This API reference is automatically generated from source code in the [Dart SDK project](https://github.com/dart-lang/sdk). If you'd like to give feedback or edit this documentation, see [Contributing](https://github.com/dart-lang/sdk/wiki/Contributing).