Swift 3 (xcode 8.3.3)
Uppercase all first characters of string
let str = "your string"
let capStr = str.capitalized
//Your String
Uppercase all characters
let str = "your string"
let upStr = str.uppercased()
//YOUR STRING
Uppercase only first character of string
var str = "your string"
let capStr = String(str.characters.prefix(1)).uppercased() + String(str.characters.dropFirst())
//Your string