Polymorphism in Dart

Polymorphism in Dart Overview

Polymorphism allows objects to take on many forms, enabling flexible and reusable code. Dart supports polymorphism through inheritance, interfaces, and method overriding, with both compile-time and runtime variations.

Key Concepts

1. Compile-time vs Runtime Polymorphism

  • Method overloading (compile-time)
  • Method overriding (runtime)
  • Static vs dynamic dispatch
  • Dart’s approach

2. Interface-based Polymorphism

  • Implicit interfaces
  • Multiple interface implementation
  • implements keyword
  • Abstract classes as interfaces

3. Overriding and Dynamic Dispatch

  • @override annotation
  • Virtual method table
  • Runtime type checking
  • Performance considerations

4. Covariant and Contravariant Types

  • Return type covariance
  • Parameter contravariance
  • Type safety rules
  • Dart 2.x type system