string - (Swift) 解析字符串的函数 (from-to)

Question

还有其他方法来解析字符串“from-to”吗？我的意思是，当我们需要一个值并且我们知道它之前和之后的字符串时。我刚刚创建了这样的函数

func parser(textToParse:String, strFrom:String, strTo:String) -> String {
        return textToParse.componentsSeparatedByString(strFrom)[1].componentsSeparatedByString(strTo)[0]
    }

它的用法就像

var s=parser("abc", strFrom: "a", strTo: "c")
//s will be "b"

Answer 1

您可以使用 substringWithRange 执行类似的操作:

func substringBetween(start: String, and end: String) -> String? {
    if let startIndex = rangeOfString(start, options: .LiteralSearch, range: nil, locale: nil)?.endIndex,
           endIndex = rangeOfString(end, options: .LiteralSearch, range: startIndex..<self.endIndex, locale: nil)?.startIndex {
        return substringWithRange(startIndex..<endIndex)
    } else {
        return nil
    }
}