Reverse String in Scala

Published on 28 April 2022 (Updated: 18 September 2022)

Reverse String in Scala

Welcome to the Reverse String in Scala page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

import scala.io.StdIn.readLine

object ReverseStringSample {
  // revese using recursive & pattern matching
  def reverseString(str: String): String = str.length match {
    case 0 => ""
    case 1 => str
    case _ => reverseString(tail(str)) ++ head(str)
  }

  def head(str: String): String = str.length match {
    case 0 => ""
    case _ => str.slice(0, 1)
  }

  def tail(str: String): String = str.length match {
    case 0 => ""
    case 1 => ""
    case _ => str.slice(1, str.length)
  }

  def main(args: Array[String]) {
    val inputStr: Option[String] = args.length match {
      case 0 => None
      case _ => Some(args(0))
    }
    inputStr.map(reverseString).map(println)
  }
}

Reverse String in Scala was written by:

If you see anything you'd like to change or update, please consider contributing.

Note: The solution shown above is the current solution in the Sample Programs repository as of Mar 22 2019 16:16:44. The solution was first committed on Mar 22 2019 12:59:04. As a result, documentation below may be outdated.

How to Implement the Solution

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How to Run the Solution

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