Callback function syntax in Swift

Question

I am attempting pass a function to another function and then have the passed function executed passing to it a variable.

Here is my code:

func showSt         


        

Answer 1

I use this way :

ViewController1

destination.callback = { (id) -> Void in
            print("callback")
            print(id)
        }

ViewController2

var callback: ((_ id: Int) -> Void)?
callback?(example_id)