Just call componentsSeparatedByString method on your fullName
import Foundation
var fullName: String = "First Last"
let fullNameArr = fullName.componentsSeparatedByString(" ")
var firstName: String = fullNameArr[0]
var lastName: String = fullNameArr[1]
Update for Swift 3+
import Foundation
let fullName = "First Last"
let fullNameArr = fullName.components(separatedBy: " ")
let name = fullNameArr[0]
let surname = fullNameArr[1]