1.String.Index String.Index表示一个位置,使用String与String.Index可以获取该位置的Character let str = "123456789" let zero = String.Index.init(encodedOffset: 0) let five = String.Index.init(encodedOffset: 5) print(str[zero]) //输出 1 print(str[five]) //输出 6 如上所示,我们构…
截取字符串 let deviceStr = deviceInfoLabel.attributedText?.string var device = "" if let len : Range<String.Index> = deviceStr?.range(of: "#"){ let range :Range<String.Index> = (deviceStr?.startIndex)! ..< len.lowerBound dev…