Swift - Optionals

Optionals

var name: String name = nil

Output

error: 'nil' cannot be assigned to type 'String'

var name: String? name = nil

Forced Unwrapping

var address: String? address = "Chennai" var message: String = address! //forced unwrapping print(message)

Optional Binding

var address: String? if let city = address { print (city) } else { print ("City name is empty") }

Implicit Unwrapping

var address: String! address = "Chennai" var message: String = address //implicit unwrapping print(message)