The Dart SDK often contains experimental features, which you can try by passing flags to Dart tools.

To use an experiment with Dart SDKcommand line tools, pass the corresponding flag to the tool.

For example, to enable the experimentssuper-mixins andno-slow-checks, add those flags to thedart command:

$dart run --enable-experiment=super-mixins,no-slow-checks bin/main.dart

Or to theflutter command:

$flutter run --enable-experiment=super-mixins,no-slow-checks

To enable experiments affecting analysis, use theenable-experiment key in theanalysis options file. Here's an example of enabling the experimentssuper-mixins andno-slow-checks inanalysis_options.yaml:

analyzer:enable-experiment:-super-mixins-no-slow-checks

To enable experiments related to running or debugging apps in IDEs, edit the launch configuration.

Inlaunch.json underconfigurations, add a newtoolArgs key containing the desired flags. Example:

"configurations":[{"name":"Dart","program":"bin/main.dart","request":"launch","type":"dart","toolArgs":["--enable-experiment=super-mixins,no-slow-checks",],}]

For more information, consult the documentation forVS Code launch configurations.

UnderVMOptions add the desired flags. Example:

<component name="ProjectRunConfigurationManager"><configuration default="false" name="Run main" type="DartCommandLineRunConfigurationType" factoryName="Dart Command Line Application"><option name="VMOptions" value="--enable-experiment=non-nullable" /><option name="filePath" value="$PROJECT_DIR$/bin/main.dart" /><method v="2" /></configuration></component>

For more information, consult the instructions forAndroid Studio run/debug configurations.

• For a complete list of experiments, see the Dart SDK fileexperimental_features.yaml.
• For information on procedures and expectations for experiment flags, see the documentation of theprocess for changes that are behind experimental flags.