regex - 如何在 NSRegularExpression 中找到匹配的组

Question

我有一个包含多个捕获组的正则表达式语句，这些捕获组由 | 分隔运算符(operator)。如何找出匹配的捕获组？对于这个例子，我能想到的唯一方法是计算匹配的字符数。

var string = "1234567897"
var pattern = "(^\\d{9}$)|(^\\d{10}$)|(^\\d{13}$)|(^[a-zA-Z]{2}\\d{9}[a-zA-Z]{2}$)"

var myRegex = NSRegularExpression(pattern: pattern, options: nil, error: nil)!

if let myMatch = myRegex.firstMatchInString(string, options: nil,
    range: NSRange(location: 0, length: string.utf16Count)) {
        println((string as NSString).substringWithRange(myMatch.rangeAtIndex(0)))

}

Answer 1

我写了一段适用于我的示例的代码。我相信它可以写成更好的方式，但它现在有效。

swift 2.3

var string = "123456789"
var pattern = "(^\\d{9}$)|(^\\d{10}$)|(^\\d{13}$)|(^[a-zA-Z]{2}\\d{9}[wW]{2}$)"

var myRegex = try! NSRegularExpression(pattern: pattern, options: [])

if let myMatch = myRegex.firstMatchInString(string, options: NSMatchingOptions.init(rawValue: 0), range: NSRange(location: 0, length: string.utf16.count)) {
    var matchedGroup = 0

    for var i in 1..<myMatch.numberOfRanges {
        if myMatch.rangeAtIndex(i).length != 0 {
            matchedGroup = i
            break
        }

    }
    print(matchedGroup)
    print((string as NSString).substringWithRange(myMatch.rangeAtIndex(0))) //whatever the range you want to print

}

swift 3

var string = "123456789"
var pattern = "(^\\d{9}$)|(^\\d{10}$)|(^\\d{13}$)|(^[a-zA-Z]{2}\\d{9}[wW]{2}$)"

var myRegex = try! NSRegularExpression(pattern: pattern, options: [])

if let myMatch = myRegex.firstMatch(in: string, options: NSRegularExpression.MatchingOptions.init(rawValue: 0), range: NSRange(location: 0, length: string.utf16.count)) {
    var matchedGroup = 0

    for var i in 1..<myMatch.numberOfRanges {
        if myMatch.rangeAt(i).length != 0 {
            matchedGroup = i
            break
        }

    }
    print(matchedGroup)
    print((string as NSString).substring(with: myMatch.rangeAt(0))) //whatever the range you want to print

}