在Scala中打印Tuples字符串的长度

4 回答

• 0

  在Scala中打印Tuples字符串的长度

  val tuples = List((1, "alpha"), (2, "beta"), (3, "gamma"), (4, "zeta"), (5, "omega"))
  println(tuples.map(x => (x._2, x._2.length)))
  //List((alpha,5), (beta,4), (gamma,5), (zeta,4), (omega,5))
  

  我想打印相应长度为4的所有字符串

  您可以首先 filter 然后 print as

  val tuples = List((1, "alpha"), (2, "beta"), (3, "gamma"), (4, "zeta"), (5, "omega"))
  tuples.filter(_._2.length == 4).foreach(x => println(x._2))
  

  它应该打印

  beta
  zeta
  

  回复于 2024-04-29T17:34:09+08:00
• 1

  您可以将 Tuple 转换为 List ，然后根据需要进行映射和过滤：

  tuple.productIterator.toList
  .map{case (a,b) => b.toString}
  .filter(_.length==4)
  

  例：

  对于给定的输入：

  val tuple = ((1, "alpha"), (2, "beta"), (3, "gamma"), (4, "zeta"), (5, "omega"))
  tuple: ((Int, String), (Int, String), (Int, String), (Int, String), (Int, String)) = ((1,alpha),(2,beta),(3,gamma),(4,zeta),(5,omega))
  

  输出：

  List[String] = List(beta, zeta)
  

  回复于 2024-04-29T17:34:09+08:00
• 0

  假设你有一个元组列表，你需要所有字符串长度等于4的值 .

  您可以在列表上执行过滤：

  val filteredList = list.filter(_._2.length == 4)
  

  然后迭代每个元素以打印它们：

  filteredList.foreach(tuple => println(tuple._2))
  

  回复于 2024-04-29T17:34:09+08:00
• 1

  这是实现这一目标的方法

  scala> val x = ((1, "alpha"), (2, "beta"), (3, "gamma"), (4, "zeta"), (5, "omega"))
  x: ((Int, String), (Int, String), (Int, String), (Int, String), (Int, String)) = ((1,alpha),(2,beta),(3,gamma),(4,zeta),(5,omega))
  
  scala> val y = x.productIterator.toList.collect{
    case ele : (Int, String) if ele._2.length == 4 => ele._2
  }
  y: List[String] = List(beta, zeta)
  

  回复于 2024-04-29T17:34:09+08:00