Proper way to concatenate optional swift strings?

Question

Let's assume I've got a Person class instance named person with first and last name properties which are both optional strings.

Now I want to construct a fullName string that contains either just their first or last name (if that's all that is available), or if we have both, their first and last name with a space in the middle.

var fullName : String? if let first = person.first {     name = first } if let last = person.last {     if name == nil {         name = last     } else {         name! += " " + last     } } 

or

var name = "" if let first = person.first {     name = first } if let last = person.last {     name = name.characters.count > 0 ? name + " " + last : last } 

Are we just supposed to nest if let's? Nil coalescing seems appropriate but I can't think of how to apply it in this scenario. I can't help but feeling like I'm doing optional string concatenation in an overly complicated way.

Answer 1

compactMap would work well here, combined with .joined(separator:):

let f: String? = "jo" let l: String? = "smith"  [f,l] // "jo smith"   .compactMap { $0 }   .joined(separator: " ") 

It doesn't put the space between if one is nil:

let n: String? = nil  [f,n] // "jo"   .compactMap { $0 }   .joined(separator: " ")