fold in kotlin code example

Example 1: fold kotlin

package com.bezkoder.kotlin.fold

fun main(args: Array<String>) {

  println(listOf(1, 2, 3, 4, 5).fold(0) { total, item -> total + item })
  // 15

  println(listOf(1, 2, 3, 4, 5).foldRight(0) { item, total -> total + item })
  // 15

  println(listOf(1, 2, 3, 4, 5).fold(1) { mul, item -> mul * item })
  // 120

  println(listOf(1, 2, 3, 4, 5).foldRight(1) { item, mul -> mul * item })
  // 120

  println(listOf(0, 1, 2, 3, 4, 5)
          .foldIndexed(0) { index, total, item -> if (index % 2 == 0) (total + item) else total })
  // 6

  println(listOf(0, 1, 2, 3, 4, 5)
          .foldRightIndexed(0) { index, item, total -> if (index % 2 == 0) (total + item) else total })
  // 6
}

Example 2: kotlin fold

listOf(1, 2, 3).fold(0) { sum, element -> sum + element }