What are delegates and events in C#?

Question

Accepted Answer

**Delegates** — type-safe function pointers. **Events** — notification mechanism. **Delegates:** ```csharp // Custom delegate public delegate int MathOperation(int a, int b); // Usage MathOperation add = (a, b) => a + b; int result = add(5, 3); // 8 ``` **Built-in delegates:** ```csharp Func square = x => x * x; Action print = Console.WriteLine; Predicate isPositive = x => x > 0; ``` **Events:** ```csharp public class Button { public event EventHandler Clicked; public void OnClick() { Clicked?.Invoke(this, EventArgs.Empty); } } // Subscribe button.Clicked += (sender, args) => Console.WriteLine("Clicked!"); ``` **Best practices:** - Use Func/Action instead of custom delegates. - Use events for notifications. - Always check for null before invoking.

C#: What are delegates and events in C#?