Scala Collections - FoldRight Method

foldRight() method is a member of TraversableOnce trait, it is used to collapse elements of collections. It navigates elements from Right to Left order.

Syntax

The following is the syntax of foldRight method.

def foldRight[B](z: B)(op: (B, A) ? B): B

Here, fold method takes associative binary operator function as a parameter. This method returns the resulted value.

Usage

Below is an example program of showing how to use foldRight method −

Example

object Demo {
   def main(args: Array[String]) = {
      val list = List(1, 2, 3 ,4)
      //apply operation to get sum of all elements of the list
      val result = list.foldRight(0)(_ + _)
      //print result
      println(result)      
   }
}

Here we've passed 0 as initial value to foldRight function and then all values are added. Save the above program in Demo.scala. The following commands are used to compile and execute this program.

Command

\>scalac Demo.scala
\>scala Demo

Output

10