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iOS Swift Closures Functions as First Class Citizens Higher Order Functions

Michael Moghadas
Michael Moghadas
5,484 Points
Posted by Michael Moghadas
Michael Moghadas
5,484 Points

stuck @ this challenge.. https://teamtreehouse.com/library/swift-closures/functions-as-first-class-citizens/higher-or

my answer to the challenge seems to work in xcode(playground)..

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

let mO = mathOperation() mO(13, 10)

// 3

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

2 Answers

Farhad Mohammad Afzali
Farhad Mohammad Afzali
5,007 Points

Hi, here is a very well explained solution to this challenge.

https://teamtreehouse.com/community/im-having-trouble-with-the-calling-a-function-with-a-function-argument-i-have-reviewed-the-documentation-for-swift