Scala List :::() operator with example Last Updated : 26 Jul, 2019 Improve Improve Like Article Like Save Share Report The :::() operator in Scala is utilized to join the List in the argument to the another List. Method Definition: def :::(prefix: List[A]): List[A] Return Type: It returns a list after joining one list to the another one. Example #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) } } Output: List(4, 5, 6, 1, 2, 3) Example #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) } } Output: List(1, 2, 3) Like Article Suggest improvement Previous Scala List addString() method with a separator with example Next Scala List apply() method with example Share your thoughts in the comments Add Your Comment Please Login to comment...