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iOS Swift Closures Functions as First Class Citizens Higher Order Functions

Posted by ch11
ch11
3,901 Points

Not sure how to ask a good question when I am not getting good feedback on the problem and have limited characters.....

I think the code says it all...

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

let difference = mathOperation(differenceBetweenNumbers, 3, 2)

// Enter your code below

1 Answer

Steven Deutsch
Steven Deutsch
21,046 Points
Steven Deutsch
Steven Deutsch
21,046 Points

Hey Charles Hieger,

I just reformatted your code a bit. I added spaces between the parameter names and parameter types. I removed the parentheses from your return type. I also added underscores before the local names of your parameters in the mathOperator function. This is to omit the requirement to label them when we make the function call.

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

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

let difference = mathOperation(differenceBetweenNumbers, 3, 2)

Good Luck!