can I split a numeric string using multiple separators in a Swift closure?

Question

I have a string array with fractional numbers and decimal numbers.

    let stringArray = [ \"0.0\", \"193.16\", \"5/4\", \"503.42\", \"696.58\", \"25/16\", \         


        

Answer 1

Split by more than one separator

Using split

Swift 4

let s = "[0, 1, 2, 1]"
let splitted = s.characters.split { [",", "[", "]"].contains($0.description) }

Swift 3

let s = "[0, 1, 2, 1]"
let splitted = s.characters.split { [",", "[", "]"].contains($0.description) }

Swift 2

let s = "[0, 1, 2, 1]"
let splitted = s.characters.split(isSeparator: {[",", "[", "]"].contains($0)}) }

---

Using characterSet

Swift 4

let str = "[0, 1, 2, 1]"
let separatorSet = CharacterSet(charactersIn: ",[]")
let comps = str.components(separatedBy: separatorSet)

Swift 3

let str = "[0, 1, 2, 1]"
let separatorSet = CharacterSet(charactersInString: ",[]")
let comps = str.components(separatedBy: separatorSet)

Swift 2

let str = "[0, 1, 2, 1]"
let separatorSet = NSCharacterSet(charactersInString: ",[]")
let comps = str.componentsSeparatedByCharactersInSet(separatorSet)

---

No matter what method we will use, and as a result, you will receive array. Without the information, which separator was used

If you need only convert String to Double then

let array = stringArray.compactMap { element -> Double? in
    if let value = Double(element) {
        return value
    }
    let parts = element.components(separatedBy: "/")
    guard parts.count == 2, 
          let dividend = Double(parts[0]), 
          let divisor = Double(parts[1]), 
          divisor != 0
    else {
        return nil
    }
    return dividend / divisor
}