# Welcome!

Welcome to the Dart API reference documentation, covering the Dart core libraries. These include:

- dart:core: Core functionality such as strings, numbers, collections, errors, dates, and URIs.
- dart:io: I/O for non-web apps.
- dart:async: Functionality for asynchronous programming with futures, streams, and zones.

You'll also find reference documentation covering Dart's various platform interoperability options, such as:

- dart:js_interop: Library including a sound type hierarchy and helper functions for interoperability with JavaScript.
- package:web: DOM manipulation for web apps.
- dart:ffi: Foreign function interfaces for interoperability with the C language.

The core libraries - except for `dart:core` - must be imported before they're available for use:

    import 'dart:math';

Additionally, you can find Dart packages at pub.dev.

## Language docs

The main site for learning and using Dart is dart.dev. Check out these pages:

- Dart overview
- Dart language documentation
- Library tour
- Tutorials

This API reference is generated from the SDK source at dart-lang/sdk. If you'd like to give feedback on or edit this documentation, see Contributing.

## Libraries

### Core

dart:async
  Support for asynchronous programming, with classes such as Future and Stream.
dart:collection
  Classes and utilities that supplement the collection support in dart:core.
dart:convert
  Encoders and decoders for converting between different data representations, including JSON and UTF-8.
dart:core
  Built-in types, collections, and other core functionality for every Dart program.
dart:developer
  Interact with developer tools such as the debugger and inspector.
dart:math
  Mathematical constants and functions, plus a random number generator.
dart:typed_data
  Lists that efficiently handle fixed sized data (for example, unsigned 8 byte integers) and SIMD numeric types.

### VM

dart:ffi
  Foreign Function Interface for interoperability with the C programming language.
dart:io
  File, socket, HTTP, and other I/O support for non-web applications.
dart:isolate
  Concurrent programming using isolates: independent workers that are similar to threads but don't share memory, communicating only via messages.
dart:mirrors
  Basic reflection in Dart, with support for introspection and dynamic invocation.

### Web

package:web open_in_new
  This package exposes browser APIs. It's intended to replace dart:html and similar Dart SDK libraries. It will support access to browser APIs from Dart code compiled to either JavaScript or WebAssembly.
dart:js_interop
  Interoperability, "interop" for short, with JavaScript and browser APIs.
dart:js_interop_unsafe
  Utility methods to manipulate JavaScript objects dynamically.

### Web (Legacy)

dart:html
  HTML elements and other resources for web-based applications that need to interact with the browser and the DOM (Document Object Model).
dart:indexed_db
  A client-side key-value store with support for indexes.
dart:js
  Low-level support for interoperating with JavaScript.
dart:js_util
  Utility methods to manipulate `package:js` annotated JavaScript interop objects in cases where the name to call is not known at runtime.
dart:svg
  Scalable Vector Graphics: Two-dimensional vector graphics with support for events and animation.
dart:web_audio
  High-fidelity audio programming in the browser.
dart:web_gl
  3D programming in the browser.