reversing a List – Clear ur Doubt

Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a simple program to reverse a List of elements without using utility method(reverse) in Scala. Let’s look at the program:

package com.clearurdoubt

object Reversing {
  
  def main(args: Array[String]) {
    val list = List(3,4,5,1,2,3) 
    val rev = reversed(list)
    
    println(rev + " @@ " + list.reverse)
  }
  
  def reversed(input: List[Int]): List[Int] = input match {    
    case List() => input
    case x :: xs => reversed(xs) ::: List(x)
  }   
}

package com.clearurdoubt

object Reversing {

def main(args: Array[String]) {

val list = List(3,4,5,1,2,3)

val rev = reversed(list)

println(rev + " @@ " + list.reverse)

}

def reversed(input: List[Int]): List[Int] = input match {

case List() => input

case x :: xs => reversed(xs) ::: List(x)

}

Output: Happy Learning. Please leave a reply Read more

S	M	T	W	T	F	S
1	2	3	4	5	6	7
8	9	10	11	12	13	14
15	16	17	18	19	20	21
22	23	24	25	26	27	28
29	30

Tag: reversing a List

How to reverse a List elements without using utility method in Scala