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iOS Swift Closures Functions as First Class Citizens Higher Order Functions

Posted by Leonardo Santos
Leonardo Santos
5,290 Points

The code works in Playground, but not in exercise screen

The attached code is working in Playground, but in exercise, it returns a bummer alert.

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

let difference: Int = mathOperation(differenceBetweenNumbers, 7, 4)