获取两个字符串之间的字符串Swift答案

【问题标题】：Get string between two strings Swift获取两个字符串之间的字符串Swift
【发布时间】：2018-09-26 07:08:52
【问题描述】：

我有以下字符串：

"Notes[9219:1224244] [BoringSSL] Function boringssl_context_get_peer_sct_list: line 1757 received sct extension length is less than sct data length [[["encendedor","lighter",null,null,1]],null,"en"]"

我只想提取第一次出现引号之间的字符串，在本例中为“enendedor”。我尝试了下面的代码，我从this question. 理解的

//finalTrans has the full string that needs to be shortened
let finalTrans = (String(data: data, encoding: .utf8)!)
let regex = try! NSRegularExpression(pattern:"[[[(.*?),", options: [])
var results = [String]()
regex.enumerateMatches(in: finalTrans, options: [], range: NSMakeRange(0, finalTrans.utf16.count)) { result, flags, stop in
                if let r = result?.range(at: 1), let range = Range(r, in: finalTrans) {
                results.append(String(finalTrans[range]))
                }
            }
//prints the new string
 print(results)

我目前收到此错误：

Thread 6: Fatal error: 'try!' expression unexpectedly raised an error: Error Domain=NSCocoaErrorDomain Code=2048 "The value “[[[(.*?),” is invalid." UserInfo={NSInvalidValue=[[[(.*?),}

如何正确提取此字符串？谢谢您的帮助。

【问题讨论】：

stackoverflow.com/questions/31725424/… 上的各种解决方案（带和不带正则表达式）。
正则表达式需要所有[被转义。 .*? 也没有意义

标签： swift string substring

【解决方案1】：

您还可以使用范围在两个字符串之间进行切片。

extension String {

    func slice(from: String, to: String) -> String? {

        return (range(of: from)?.upperBound).flatMap { substringFrom in
            (range(of: to, range: substringFrom..<endIndex)?.lowerBound).map { substringTo in
                String(self[substringFrom..<substringTo])
            }
        }
    }
}

let slicedString = yourString.slice(from: "\"", to: "\"") // Optional("encendedor")

【讨论】：

【解决方案2】：

使用components(separatedBy:):

var str = "Notes[9219:1224244] [BoringSSL] Function boringssl_context_get_peer_sct_list: line 1757 received sct extension length is less than sct data length [[[\"encendedor\",\"lighter\",null,null,1]],null,\"en\"]"

str.components(separatedBy: "\"")[1] // "encendedor"

【讨论】：