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cjavdev's solution

to Reverse String in the Java Track

Published at Mar 04 2019 · 0 comments
Test suite


This exercise has changed since this solution was written.

Reverse a string

For example: input: "cool" output: "looc"

Java Tips

For more help on how to solve this exercise, please refer to the tutorial provided as part of the hello world exercise: TUTORIAL.md

Running the tests

You can run all the tests for an exercise by entering

$ gradle test

in your terminal.


Introductory challenge to reverse an input string https://medium.freecodecamp.org/how-to-reverse-a-string-in-javascript-in-3-different-ways-75e4763c68cb

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.


import org.junit.Ignore;
import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class ReverseStringTest {

    public void testAnEmptyString() {
        assertEquals("", new ReverseString().reverse(""));

    @Ignore("Remove to run test")
    public void testAWord() {
        assertEquals("tobor", new ReverseString().reverse("robot"));

    @Ignore("Remove to run test")
    public void testACapitalizedWord() {
        assertEquals("nemaR", new ReverseString().reverse("Ramen"));

    @Ignore("Remove to run test")
    public void testASentenceWithPunctuation() {
        assertEquals("!yrgnuh m'I", new ReverseString().reverse("I'm hungry!"));

    @Ignore("Remove to run test")
    public void testAPalindrome() {
        assertEquals("racecar", new ReverseString().reverse("racecar"));

class ReverseString {

    String reverse(String inputString) {
      if(inputString.length() == 0) {
        return "";

      String outputString = new String(inputString);
      String reversed = reverse(inputString.substring(1, inputString.length()));
      return reversed + inputString.substring(0, 1);


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