使用regex的scala捕获组

下面是一个如何访问的示例 group(1) 每场比赛:

val string = "one493two483three"
val pattern = """two(\d+)three""".r
pattern.findAllIn(string).matchData foreach {
   m => println(m.group(1))
}

这张照片 "483" ( as seen on ideone.com )

环视选项

根据模式的复杂性,还可以使用lookarounds 只有 匹配您想要的部分。它看起来像这样:

val string = "one493two483three"
val pattern = """(?<=two)\d+(?=three)""".r
pattern.findAllIn(string).foreach(println)

上面也打印了 “483” ( as seen on ideone.com )

工具书类

• regular-expressions.info/Lookarounds

val string = "one493two483three"
val pattern = """.*two(\d+)three.*""".r

string match {
  case pattern(a483) => println(a483) //matched group(1) assigned to variable a483
  case _ => // no match
}

你想看看 group(1) ,您当前正在查看 group(0) ,即“整个匹配字符串”。

见 this regex tutorial .

def extractFileNameFromHttpFilePathExpression(expr: String) = {
//define regex
val regex = "http4.*\\/(\\w+.(xlsx|xls|zip))$".r
// findFirstMatchIn/findAllMatchIn returns Option[Match] and Match has methods to access capture groups.
regex.findFirstMatchIn(expr) match {
  case Some(i) => i.group(1)
  case None => "regex_error"
}
}
extractFileNameFromHttpFilePathExpression(
    "http4://testing.bbmkl.com/document/sth1234.zip")