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iOS Closures in Swift 2 First Class Functions Higher Order Functions

Batuhan Ertas
Batuhan Ertas
1,159 Points

can anyone say what's wrong with that code?

I could not figure out the wrong part of this code.

// Enter your code below

extension String{

  func modify(input: String -> String ) -> String 

      return input(self)


func firstLetter (input:String) -> String
  var arr:[String] = input.characters.map { String($0) }
  return arr[0]


let value:String = String("tugce").modify(firstLetter)