Explain what forced unwrapping of an optional in Swift is and in what situations it is used?

Force unwrapping of an optional in Swift is an operation to extract the value from an optional type using the exclamation mark !. It is used when the programmer is sure that the optional contains a value and wants to access it directly.

For example:

let optionalString: String? = "Hello"
let forcedString: String = optionalString! // force unwrapping

If the optional is nil, force unwrapping will cause a runtime error (crash).

It is used in situations where it is guaranteed that the value is not nil, such as after a check or when working with APIs where the value is always present. However, it is recommended to use safe unwrapping with if let or guard let to avoid crashes.