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iOS Swift Closures Functions as First Class Citizens Higher Order Functions

László Győri
László Győri
82,430 Points
Posted by László Győri
László Győri
82,430 Points

Higher Order Functions challenge step 2

For some reason my solution for step 2 isn't being accepted and I'm not sure why. The code itself works so it's more likely I missed some specific requirement, at least that's my best guess. Any help would be appreciated.

higherOrderFunctions.swift 
/** 
  For this code challenge, let’s define a math operation as a function that 
  carries out some work on two integers and returns an integer as well. An 
  example is the function below, `differenceBetweenNumbers`, which takes two 
  integers and calculates the difference between the numbers. After calculating, 
  it returns the difference.
*/

func differenceBetweenNumbers(a: Int, b:Int) -> (Int) {
  return a - b
}

// Enter your code below
func mathOperation(f: (Int, Int) -> (Int), a: Int, b: Int)  -> (Int) {
  return f(a,b)
}

let difference = mathOperation(differenceBetweenNumbers, 20, 11)

1 Answer

Martin Wildfeuer
PLUS
Martin Wildfeuer
Courses Plus Student 11,071 Points
Martin Wildfeuer
Martin Wildfeuer
Courses Plus Student 11,071 Points

That seems to be a bug with the code check on this site, there is nothing wrong with your code. Although you can pass the first task, the second part will require you to remove parenthesis from the return types:

func mathOperation(f: (Int, Int) -> Int, a: Int, b: Int) -> Int {
  return f(a,b)
}

let difference = mathOperation(differenceBetweenNumbers, 20, 11)

My personal preference is to omit parenthesis with single return values, anyhow.