CODEWITHSUNDEEP
swiftalgorithm
PruitIgoe
PruitIgoe

Reputation: 6384

Swift: Get next highest number that ends in zero

I have to run some algorithms on certain health industry numbers for validations. One of them requires checking if a total at a certain point ends in zero, if not get the next highest number that ends in zero. I have this code but am wondering if there is a better way to do it:

let strTotal = String(iTotal)
    var iSubtractor = iTotal

    if Int(String(strTotal.last!))! != 0 {
        var bIsZeroEnding = false

        repeat {

            iSubtractor += 1
            let strSubstractor = String(iSubtractor)
            if Int(String(strSubstractor.last!))! == 0 {
                bIsZeroEnding = true
            }

        } while !bIsZeroEnding
    }

Doh...I do see the typo in my var name...strSubstractor... :D

Upvotes: 0

Views: 322

Answers (3)

TheTiger
TheTiger

Reputation: 13354

You can use ceil. It works with both (non-negative) and (negative) numbers.

extension CGFloat {
    func nearest(to num: CGFloat) -> CGFloat {
        return num * ceil(self/num)
    }
}

let value: CGFloat = 53.0
print(value.nearest(to: 10))

output: 60.0

Alternatively for pure int you can get it with the help of remainder operator (%).

let value: Int = 33
let rem: Int = value%10

// Here, If rem == 0 that means number is fully divisible by 10 (Contains 0 at last)
let result: Int = (rem == 0) ? value : value + (10 - rem)

Upvotes: 1

Martin R
Martin R

Reputation: 539925

I have this code but am wondering if there is a better way to do it

Yes, there is. Rounding up a (non-negative) integer to the next multiple of 10 can be far more simply done with

let roundedNumber = ((oldNumber + 9)/10) * 10

without the need for any conversion to strings. We add 9 and then round down to the next multiple of 10 (using the fact that integer division truncates the result to an integer result).

Upvotes: 4

Akshansh Thakur
Akshansh Thakur

Reputation: 5341

This is all you need to do:

var desiredNumber = ceil(Double(iTotal)/10)*10

How this method works:

  • Let's assume our original number is 37. If we divide it by 10, we get 3.7.
  • If we ceil 3.7, we get 4. Multiplying it by the divider will get us 40. This works with every divider.

Upvotes: 1

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