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iOS Swift Closures Functions as First Class Citizens Higher Order Functions

Mor Koshokaro
Mor Koshokaro
5,466 Points

Problem with the closures code challange :<

Hi, I've answered the challenge and it says it's wrong all the time. I've even checked in a playground if it compiles right and it does and there are no errors in the console

The instructions are to use any two numbers so I've hard coded two numbers and it still doesn't solve it. I've tried assigning something like this:

let op = differenceBetweenNumbers

let difference = mathOperation(op, 10, 7)

with no luck still.. Please help me :< Thanks

  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(operation: (Int, Int) -> (Int), a: Int, b: Int) -> Int {
    return operation(a, b)

let difference = mathOperation(differenceBetweenNumbers, 10, 7)

2 Answers

You need to use the differenceBetweenNumbers function as the parameter for the mathOperation function instead of making your own function. The compiler will accept your code for the first challenge but won't for the second one. Also, remove the set parentheses enclosing the return type for the parameter function. If you can't figure it out, I will supply the code for you.

Mor Koshokaro
Mor Koshokaro
5,466 Points

It worked! thank you so much!

Your welcome