Why create “Implicitly Unwrapped Optionals”, since that implies you know there's a value?

Question

Why would you create a \"Implicitly Unwrapped Optional\" vs creating just a regular variable or constant? If you know that it can be successfully unwrapped then why create a

Answer 1

If you know for sure, a value return from an optional instead of nil, Implicitly Unwrapped Optionals use to directly catch those values from optionals and non optionals can't.

//Optional string with a value
let optionalString: String? = "This is an optional String"

//Declaration of an Implicitly Unwrapped Optional String
let implicitlyUnwrappedOptionalString: String!

//Declaration of a non Optional String
let nonOptionalString: String

//Here you can catch the value of an optional
implicitlyUnwrappedOptionalString = optionalString

//Here you can't catch the value of an optional and this will cause an error
nonOptionalString = optionalString

So this is the difference between use of

let someString : String! and let someString : String