Junior — Middle

What is the role of the Extension class in the Dart language and why is it used?

sobes.tech AI

Answer from AI

In Dart, the Extension class is used to add new methods and properties to existing types without the need for inheritance or modifying the original class code.

This allows extending the functionality of standard or third-party classes, making the code more expressive and convenient.

Example of usage:

extension NumberParsing on String {
  int toIntOrZero() {
    return int.tryParse(this) ?? 0;
  }
}

void main() {
  String s = "123";
  print(s.toIntOrZero()); // Outputs 123
  print("abc".toIntOrZero()); // Outputs 0
}

Thus, Extension helps to add useful methods to existing types without modifying them.

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