Topic 14. Delegates, lambda expressions, and events

Goal: become familiar with delegates, lambda expressions, and events in C#; learn to pass behavior into methods with Action, Func, and Predicate<T>, create higher-order functions and closures, declare and raise events according to the standard .NET pattern, and subscribe to and unsubscribe from them.

Lecture contents

1. Delegates — A method as a value · Delegates · Built-in delegates
2. Lambda expressions and closures — Lambda expressions · Closures · Higher-order functions
3. Events — Events
4. Examples and common mistakes — Example programs · Common mistakes

Practice and review

• Practice — 3 worked examples with complete code and output
• Tasks — 30 variants, each with tasks at three difficulty levels
• Summary — conclusions, self-check questions, and useful links