Extension In Dart

Dart Extension Method

In Dart, you can extend the functionality of a class by using extension. It is a new feature in Dart 2.7.0. It is similar to extension methods in C# and Kotlin. It is also similar to the concept of mixins in Dart.

How To Use Extension In Dart

Here we are extending the functionality of String class. We are adding a new method capitalize to the String class. We are using extension keyword to extend the functionality of String class.

void main(){
  String name = "john";
  print(name.capitalize());
}

extension StringExtension on String{
  String capitalize(){
    return "${this[0].toUpperCase()}${this.substring(1)}";
  }
}

John

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Watch this video to learn more about extension in Dart programming language.