Scala List :::()运算符与示例

Scala 中的:::()运算符用于将参数中的 List 连接到另一个 List。

Method Definition: def :::(prefix: List[A]): List[A]

Return Type: It returns a list after joining one list to the another one.

示例 #1：

// Scala program of :::()
// method
  
// Creating object
object GfG
{ 
  
    // Main method
    def main(args:Array[String])
    {
      
        // Creating two lists
        val m1 = List(1, 2, 3)
        val m2 = List(4, 5, 6)
          
        // Applying ::: operator
        val res = m1.:::(m2)
          
        // Displays output
        println(res)
      
    }
}

输出：

List(4, 5, 6, 1, 2, 3)

示例 #2：

// Scala program of :::()
// method
  
// Creating object
object GfG
{ 
  
    // Main method
    def main(args:Array[String])
    {
      
        // Creating two lists
        val m1 = List(1, 2, 3)
        val m2 = List()
          
        // Applying ::: operator
        val res = m1.:::(m2)
          
        // Displays output
        println(res)
      
    }
}

输出：

List(1, 2, 3)