1、Develop Efficiently by Dart 3ShanghaiAbout MeYii Chen 陈虔逸 Organizer of FlutterTaipeiLead HerFIT and VIBZyiichenhiFlutter 爱好者、推广者Agenda Dart NewsDart TimelineFeatures ReviewExamplesDart NewsState of the Developer Nation Q3 2023|SlashData|Some rights reservedttNull safety previewFirst release with nul

2、l safety launched to enable experimentation.July 2020Nov 2020Mar 2021Sep 2021Feb 2023May 2023Dart TimelineNull safety betaNull safety is feature complete.Migration of existing code begins.Null safety stable(Dart 2.12)Null safety is available in stable.Migration off to a good start94%of the top-1000

3、migrated.Dart 3 releasedDart now has 100%sound null safety.99%of the top-1000 has been migrated.Dart 3.2Nov 2023Dart 3 alphaGetting ready for Dart 3.98%of the top-1000 has been migrated.Features ReviewRecord AnonymousImmutableSupport multiple valueNo need classPattern Matching If-Case MatchingDestru

4、cturingSwitch Expression use Pattern Matching and Destructuringuse when for conditionClass Modifier base Only can extendinterface Only can implementfinal Cant extend,implement and mixinsealed Support exhaustively checkingabstract interface class Only can implementmore.ExampleExample 11.Destructuring

5、Example 11.DestructuringExample 11.DestructuringExample 21.DestructuringExample 21.DestructuringExample 21.DestructuringExample 31.Switch Expression2.Pattern Matching3.DestructuringExample 31.Switch Expression2.Pattern Matching3.DestructuringExample 41.Switch Expression2.DestructuringExample 51.Swit

6、ch Expression2.Patter Matching3.RecordExample 51.Switch Expression2.Patter Matching3.RecordExample 51.Switch Expression2.Patter Matching3.RecordExample 61.Record2.typedef3.extensionExample 71.If-Case MatchingExample 71.If-Case MatchingExample 71.If-Case MatchingExample 81.Record2.Iterable ExtensionE

7、xample 91.Switch ExpressionExample 91.Switch ExpressionExample 101.If-Case Matching2.Class ModifierExample 101.If-Case Matching2.Class ModifierExample 11Dart 3.2:Non-null Type Promotion Give a hug to Dart 3.Dive into and get familiar.Use at the right time and good at.Have fun!Wrap UpThanks!“Dart 3 make our life easier,right?”Q/A