Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Swift Closures Functions as First Class Citizens Higher Order Functions

Mathieu HAYS
Mathieu HAYS
9,623 Points
Posted by Mathieu HAYS
Mathieu HAYS
9,623 Points

Challenge validation fail but it's working in playground.

What am I missing here ?

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
}

func mathOperation( theFunc: (Int, Int) -> (Int), nA: Int, nB: Int ) -> (Int) {
  return theFunc( nA, nB )
}

let difference = mathOperation( differenceBetweenNumbers, 5, 3 )

1 Answer