Object-Oriented Programming

Model the world with classes, objects, inheritance and interfaces.

1. 2.1

   Classes & objects

   • Fields
   • Constructors
   • Properties
   • Encapsulation
   • Classes and objects— Bundle data and behavior together by defining your own types with classes.12 min
   • Properties and encapsulation— Expose an object's data safely with properties, validation and static members.12 min
2. 2.2

   Inheritance & polymorphism

   • Base classes
   • virtual / override
   • Abstract classes
   • Inheritance— Build specialized classes on top of general ones and reuse their code.10 min
   • Polymorphism: virtual, override and abstract— Let each derived class supply its own behavior, and treat them all through their base type.12 min
3. 2.3

   Interfaces

   • Contracts
   • Multiple interfaces
   • Default implementations
   • Interfaces— Define contracts that unrelated classes can fulfil, and program against capabilities instead of concrete types.12 min
4. 2.4

   Records & structs

   • record
   • struct
   • Immutability
   • Equality
   • Records— Model immutable data with records — value equality, readable ToString and non-destructive changes.10 min
   • Structs and value semantics— Use structs for small values that are copied rather than shared.9 min