Exercism v3 launches on Sept 1st 2021. Learn more! ๐Ÿš€๐Ÿš€๐Ÿš€
Avatar of rootulp

rootulp's solution

to Reverse String in the Go Track

Published at Jun 01 2020 · 0 comments
Test suite

Reverse a string

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

Coding the solution

Look for a stub file having the name reverse_string.go and place your solution code in that file.

Running the tests

To run the tests run the command go test from within the exercise directory.

If the test suite contains benchmarks, you can run these with the --bench and --benchmem flags:

go test -v --bench . --benchmem

Keep in mind that each reviewer will run benchmarks on a different machine, with different specs, so the results from these benchmark tests may vary.

Further information

For more detailed information about the Go track, including how to get help if you're having trouble, please visit the exercism.io Go language page.


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.


package reverse

// Source: exercism/problem-specifications
// Commit: 6c95c2e reverse-string: Add a test with an even-sized word (#1519)
// Problem Specifications Version: 1.2.0

type reverseTestCase struct {
	description string
	input       string
	expected    string

var testCases = []reverseTestCase{
		description: "an empty string",
		input:       "",
		expected:    "",
		description: "a word",
		input:       "robot",
		expected:    "tobor",
		description: "a capitalized word",
		input:       "Ramen",
		expected:    "nemaR",
		description: "a sentence with punctuation",
		input:       "I'm hungry!",
		expected:    "!yrgnuh m'I",
		description: "a palindrome",
		input:       "racecar",
		expected:    "racecar",
		description: "an even-sized word",
		input:       "drawer",
		expected:    "reward",


package reverse

import (

func TestReverse(t *testing.T) {
	for _, testCase := range append(testCases, multiByteCases...) {
		if res := Reverse(testCase.input); res != testCase.expected {
			t.Fatalf("FAIL: %s(%s)\nExpected: %q\nActual: %q",
				testCase.description, testCase.input, testCase.expected, res)
		t.Logf("PASS: %s", testCase.description)

func TestReverseOfReverse(t *testing.T) {
	assertion := func(s string) bool {
		return s == Reverse(Reverse(s))
	if err := quick.Check(assertion, nil); err != nil {

func BenchmarkReverse(b *testing.B) {
	for i := 0; i < b.N; i++ {
		for _, test := range testCases {

// mutiByteCases adds UTF-8 multi-byte case,
// since the canonical-data.json (generator data source for cases_test.go)
// doesn't have any such cases.
var multiByteCases = []reverseTestCase{
		description: "a multi-byte test case",
		input:       "Hello, ไธ–็•Œ",
		expected:    "็•Œไธ– ,olleH",
package reverse

import (

// Reverse returns a string with characters in reversed order.
func Reverse(s string) string {
	chars := strings.Split(s, "")
	result := make([]string, len(s))

	for i := len(chars) - 1; i >= 0; i-- {
		result = append(result, chars[i])
	return strings.Join(result, "")

Community comments

Find this solution interesting? Ask the author a question to learn more.

What can you learn from this solution?

A huge amount can be learned from reading other peopleโ€™s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

  • What compromises have been made?
  • Are there new concepts here that you could read more about to improve your understanding?