Closure

/** 
  QUESTION 1a
  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.

  QUESTION 1b
  Using the differenceBetweenNumbers function as an input to mathOperation, 
  compute the difference between any two integers and assign the result to 
  a constant named difference.
*/

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

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

let difference = mathOperation(differenceBetweenNumbers, 1, 2)