Events and Lambda Expressions C#

What is an event in C#?

• A method that is automatically called

• A type of variable that can hold multiple data types

• A way for a class to notify other classes when something of interest happens

• A method that modifies an object

Which keyword is used to declare an event in C#?

• delegate

• event

• public

• handler

What is a delegate in the context of C# events?

• A type that defines the signature of a method that can be called when an event is raised

• A collection that stores event listeners

• A method used to handle exceptions

• A class that raises an event

How do you subscribe a method to an event in C#?

• Using the `=` operator

• Using the `+=` operator

• Using the `->` operator

• Using the `++` operator

Which of the following is a valid event declaration in C#?

• public event void MyEvent();

• public event EventHandler MyEvent;

• public delegate void MyEvent;

• public event MyHandler MyEvent()

What is the main purpose of using events in C#?

• To allow methods to return multiple values

• To provide a mechanism for communication between objects when something of interest happens

• To store a list of functions

• To handle multithreading

What happens if an event has no subscribers when it is raised?

• It causes an error

• The event is ignored

• A default handler is called

• The application crashes

Which of the following best describes an anonymous method?

• A method without a name used to handle events or delegates

• A method that is stored in a dictionary

• A method that has multiple return types

• A method that only accepts one parameter

How do you unsubscribe from an event in C#?

• Using the `=` operator

• Using the `-= ` operator

• Using the `--` operator

• Using the `+` operator

What is a lambda expression in C#?

• A concise way to write anonymous methods

• A way to declare events

• A keyword used for inheritance

• A method used for data serialization