Intermediate C#

The features that make C# expressive and safe: generics, collections, nullability and more.

1. 3.1

   Value vs reference types

   • Copy semantics
   • null
   • Nullable reference types
   • Value types vs reference types— Predict exactly what happens when variables are copied, compared and passed to methods.11 min
   • null and nullable types— Handle missing values safely with nullable types, ?., ?? and the compiler's null-safety warnings.11 min
2. 3.2

   Generics

   • Generic classes & methods
   • Constraints
   • Generics— Write classes and methods that work with any type while staying fully type-safe.12 min
3. 3.3

   Collections

   • List<T>
   • Dictionary<K,V>
   • HashSet<T>
   • Queue / Stack
   • List<T>: the everyday collection— Store, grow, search and reorder sequences of items with List<T>.11 min
   • Dictionaries and sets— Look things up by key instantly with Dictionary, and track unique items with HashSet.12 min
   • Queues and stacks— Process items in arrival order with Queue<T>, or most-recent-first with Stack<T>.10 min
4. 3.4

   Exceptions

   • try / catch / finally
   • Custom exceptions
   • When to throw
   • Exceptions— Signal and handle errors with throw, try, catch and finally — and know when not to.13 min
5. 3.5

   Modern C# features

   • Enums
   • Pattern matching
   • Extension methods
   • Tuples
   • Enums— Replace magic numbers and strings with named constants the compiler can check.9 min
   • Pattern matching— Test the shape of data — its type, properties and contents — in one readable expression.12 min
   • Extension methods and tuples— Add methods to existing types without changing them, and group values without declaring a type.10 min