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    Scala中正則表達式以及與模式匹配結(jié)合(多種方式)

    正則表達式

       //"""原生表達   val regex="""([0-9]+)([a-z]+)""".r   val numPattern="[0-9]+".r   val numberPattern="""s+[0-9]+s+""".r

    說明:.r()方法簡介:Scala中將字符串轉(zhuǎn)換為正則表達式

       /** You can follow a string with `.r`, turning it into a `Regex`. E.g.   *   * `"""Aw*""".r` is the regular expression for identifiers starting with `A`.   */   def r: Regex = r()

    模式匹配一

       //findAllIn()方法返回遍歷所有匹配項的迭代器   for(matchString <- numPattern.findAllIn("99345 Scala,22298 Spark"))    println(matchString)  

    說明:findAllIn(…)函數(shù)簡介

      /** Return all non-overlapping matches of this `Regex` in the given character    * sequence as a [[scala.util.matching.Regex.MatchIterator]],   * which is a special [[scala.collection.Iterator]] that returns the   * matched strings but can also be queried for more data about the last match,   * such as capturing groups and start position.   *    * A `MatchIterator` can also be converted into an iterator   * that returns objects of type [[scala.util.matching.Regex.Match]],   * such as is normally returned by `findAllMatchIn`.   *    * Where potential matches overlap, the first possible match is returned,   * followed by the next match that follows the input consumed by the   * first match:   *   * {{{   * val hat = "hat[^a]+".r   * val hathaway = "hathatthattthatttt"   * val hats = (hat findAllIn hathaway).toList      // List(hath, hattth)   * val pos = (hat findAllMatchIn hathaway map (_.start)).toList // List(0, 7)   * }}}   *   * To return overlapping matches, it is possible to formulate a regular expression   * with lookahead (`?=`) that does not consume the overlapping region.   *   * {{{   * val madhatter = "(h)(?=(at[^a]+))".r   * val madhats = (madhatter findAllMatchIn hathaway map {   * case madhatter(x,y) => s"$x$y"   * }).toList          // List(hath, hatth, hattth, hatttt)   * }}}   *   * Attempting to retrieve match information before performing the first match   * or after exhausting the iterator results in [[java.lang.IllegalStateException]].   * See [[scala.util.matching.Regex.MatchIterator]] for details.   *   * @param source The text to match against.   * @return  A [[scala.util.matching.Regex.MatchIterator]] of matched substrings.   * @example  {{{for (words <- """w+""".r findAllIn "A simple example.") yield words}}}   */   def findAllIn(source: CharSequence) = new Regex.MatchIterator(source, this, groupNames)

    Scala中正則表達式以及與模式匹配結(jié)合(多種方式)

    模式匹配二

       //找到首個匹配項   println(numberPattern.findFirstIn("99ss java, 222 spark,333 hadoop"))

    Scala中正則表達式以及與模式匹配結(jié)合(多種方式)

    模式匹配三

      //數(shù)字和字母的組合正則表達式   val numitemPattern="""([0-9]+) ([a-z]+)""".r   val numitemPattern(num, item)="99 hadoop"

    Scala中正則表達式以及與模式匹配結(jié)合(多種方式)

    模式匹配四

       //數(shù)字和字母的組合正則表達式   val numitemPattern="""([0-9]+) ([a-z]+)""".r   val line="93459 spark"   line match{    case numitemPattern(num,blog)=> println(num+"t"+blog)    case _=>println("hahaha...")   }  

    Scala中正則表達式以及與模式匹配結(jié)合(多種方式)

      val line="93459h spark"   line match{    case numitemPattern(num,blog)=> println(num+"t"+blog)    case _=>println("hahaha...")   }

    Scala中正則表達式以及與模式匹配結(jié)合(多種方式)

    本節(jié)所有程序源碼

      package kmust.hjr.learningScala19  /**   * Created by Administrator on 2015/10/17.   */  object RegularExpressOps {   def main(args:Array[String]):Unit={   val regex="""([0-9]+)([a-z]+)""".r//"""原生表達   val numPattern="[0-9]+".r   val numberPattern="""s+[0-9]+s+""".r   //findAllIn()方法返回遍歷所有匹配項的迭代器   for(matchString <- numPattern.findAllIn("99345 Scala,22298 Spark"))    println(matchString)   //找到首個匹配項   println(numberPattern.findFirstIn("99ss java, 222 spark,333 hadoop"))   //數(shù)字和字母的組合正則表達式   val numitemPattern="""([0-9]+) ([a-z]+)""".r   val numitemPattern(num, item)="99 hadoop"   val line="93459h spark"   line match{    case numitemPattern(num,blog)=> println(num+"t"+blog)    case _=>println("hahaha...")   }   }  }

    Scala中正則表達式以及與模式匹配結(jié)合(多種方式)

    總結(jié)

    以上所述是小編給大家介紹的Scala中正則表達式以及與模式匹配結(jié)合(多種方式),希望對大家有所幫助,如果大家有任何疑問歡迎給我留言,小編會及時回復(fù)大家的!

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