Swift 4 'substring(from:)' is deprecated: Please use String slicing subscript with a 'partial range from' operator

Question

i\'ve just converted my little app but i\'ve found this error: \'substring(from:)\' is deprecated: Please use String slicing subscript with a \'partial range from\' operator

Answer 1

In Swift 5, it is:

extension String {

    func index(from: Int) -> Index {
        return self.index(startIndex, offsetBy: from)
    }

    func substring(from: Int) -> String {
        let fromIndex = index(from: from)
        return String(self[fromIndex...])
    }

    func substring(to: Int) -> String {
        let toIndex = index(from: to)
        return String(self[..<toIndex])
    }

    func substring(with r: Range<Int>) -> String {
        let startIndex = index(from: r.lowerBound)
        let endIndex = index(from: r.upperBound)
        return String(self[startIndex..<endIndex])
    }
}