Advanced Classes

Advanced Class Features in Dart Overview#

Dart provides sophisticated class mechanisms that go beyond basic object-oriented programming. These features enable powerful patterns for code reuse, type safety, and flexible object creation.

Key Concepts#

1. Inheritance#

  • Single inheritance model
  • super keyword usage
  • Parent class initialization
  • Method overriding principles

2. Object Identity & Equality#

  • == operator overriding
  • identical() function
  • hashCode contracts
  • Equality best practices

3. Abstract Classes#

  • Partial implementations
  • Abstract methods
  • Interface enforcement
  • Base contracts

4. Sealed Classes#

  • Fixed set of subtypes
  • Exhaustive pattern matching
  • State modeling
  • Algebraic data types

5. Interface Classes#

  • Explicit interface syntax
  • Contract enforcement
  • Multiple implementation
  • API design

6. Interfaces (Implicit)#

  • Class-based interfaces
  • implements keyword
  • Loose coupling patterns
  • Testing advantages

7. Generics#

  • Type parameters
  • Collection types
  • Generic methods
  • Bounded types

8. Enums#

  • Fixed value sets
  • Enhanced enums (methods/properties)
  • Pattern matching
  • State representation

9. Mixins#

  • Code reuse
  • Multiple composition
  • on keyword restrictions
  • Linearization rules

10. Extension Methods#

  • Existing type augmentation
  • Syntax sugar
  • Utility patterns
  • Scope limitations

11. Factory Constructors#

  • Alternative instantiation
  • Object pooling
  • Cache patterns
  • Return flexibility

12. Const Constructors#

  • Compile-time constants
  • Immutable objects
  • Canonicalization
  • Performance benefits