Objective-C for loop to Swift 3 - objective-c

Question

What is the nicest and cleanest way to translate this Objective-C for-loop to Swift 3? What is best practice? Should I use a while loop?
NSInteger pageHeight = 792;
NSInteger pageWidth = 612;
for (int page=0; pageHeight * page < scrollView.frame.size.height; page++) {
// execute some code
}
I tried to work with something like this
for i in pageHeight * i < scrollView.frame.size.height {
// execute some code
}
but I cannot reuse the variable i since it cannot be used. Compiler gives the error: unresolved identifier 'i'.
EDIT: one of the reasons I asked the question was because I wanted to specifically know what the best practice is and to avoid creating an additional variable before the loop code.

Answer 1

You should use a while loop:
let pageHeight = 792
let pageWidth = 612
var page = 0
while pageHeight * page < Int(scrollView.frame.size.height) {
// execute some code
page += 1
}

Answer 2

Assuming you don't change any of the loop-related variables inside the loop, you can do it this way:
let pageHeight: Int = 792
let pageWidth: Int = 612
let pageCount = Int(scrollView.frame.size.height) / pageHeight
for page in 0..<pageCount {
}

Answer 3

As another option, here's a recursive/functional option:
func setupPages(maxHeight: CGFloat, pageHeight: CGFloat, pageNumber: Int = 0) {
guard (pageHeight * CGFloat(pageNumber)) < maxHeight else {
return
}
// do what you need to do
setupPages(maxHeight: maxHeight, pageHeight: pageHeight, pageNumber: pageNumber + 1)
}
Then in your code you can just simple call:
setupPages(maxHeight: scrollView.frame.height, pageHeight: CGFloat(pageWidth))