如何在scala中反转列表

在 Scala 中，列表定义在scala.collection.immutable包下。列表是包含不可变数据的相同类型元素的集合。我们使用 reverse函数来反转 Scala 中的列表。
以下是反转列表的示例。

• 反转一个简单的列表

  // Scala program to reverse a simple Immutable lists 
  import scala.collection.immutable._
    
  // Creating object 
  object GFG 
  { 
      // Main method 
      def main(args:Array[String]) 
      { 
          // Creating and initializing immutable lists 
          val mylist: List[String] = List("Geeks", "For",
                                  "geeks", "is", "best") 
        
          // Display the value of mylist1 
          println("Reversed List is: " + mylist.reverse) 
        
      } 
  } 
  

  输出：

  Reversed List is: List(best, is, geeks, For, Geeks)

• 使用 for 循环反转列表

  // Scala program to print reverse immutable lists 
  // using for loop
  import scala.collection.immutable._
    
  // Creating object 
  object GFG
  { 
      // Main method 
      def main(args:Array[String]) 
      { 
          // Creating and initializing immutable lists 
          val mylist: List[String] = List("Geeks", "For", "geeks", "is",
                                          "a", "fabulous", "portal")
    
          // Display the value of mylist in
          // reverse order using for loop 
          for(element<-mylist.reverse) 
          { 
              println(element) 
          } 
      } 
  } 
  

  输出：

  portal
  fabulous
  a
  is
  geeks
  For
  Geeks

• 使用 foreach 循环反转列表

  // Scala program to reverse a list
  // using foreach loop
  import scala.collection.immutable._
    
  // Creating object 
  object GFG
  { 
      // Main method 
      def main(args:Array[String]) 
      { 
          // Creating and initializing immutable lists 
          val mylist = List("Geeks", "For", "geeks", "is",
                          "a", "fabulous", "portal")
            
          print("Original list is: ")
            
          // Display the value of mylist using for loop 
          mylist.foreach{x:String => print(x + " ") }
            
          // calling reverse function
          println("\nReversed list: " + mylist.reverse)
      } 
  } 
  

  输出：

  Original list is: Geeks For geeks is a fabulous portal 
  Reversed list: List(portal, fabulous, a, is, geeks, For, Geeks)