Daily Challenge #37 - Name Swap

thepracticaldev profile image dev.to staff ・1 min read

In today's challenge, we ask that you to write a function that returns a string in which an individual's first name is swapped with their last name.

Example: nameShuffler('Emma McClane'); => "McClane Emma"

Good luck!

This challenge comes from debri on CodeWars. Thank you to CodeWars, who has licensed redistribution of this challenge under the 2-Clause BSD License!

Want to propose a challenge for a future post? Email yo+challenge@dev.to with your suggestions!


Editor guide

You mean like this? It would work for your use case, although I don't know how you want to handle things like having more than 2 names or last names?

function nameShuffler(name) {
  return name.split(" ").reverse().join(" ")

And with arrow function

const nameShuffler = string => string.split(' ').reverse().join(' ')

Yeap, a quick, little fun one liner. I love it!


There are a few answers in JavaScript already, so let's try some things in CSS 🀩

We could separate the words into <span> and, using Flexbox, change the order in which they are displayed within the parent container using the order property. It can be easily expanded to more than 2 words, but it requires that wrapping to work.

div {
  display: inline-flex;

div > span {
  margin-right: 1ch;

div span:nth-child(1) { order: 2; }
div span:nth-child(2) { order: 1; }

Without having to add any additional tags, we can use data-attributes to have the name and last name, and use the ::before and ::after to display them in inverted order. It is really simple to implement but not too extendable:

<div data-first="Name" data-last="Surname"></div>

div::before {
  content: attr(data-last) ' ';

div::after {
  content: attr(data-first);

Also without having any additional tags, we can play with multiple text-shadows and positioning to replicate the words in inverted order. For this solution, you need to know the size of each word, and it doesn't work for more than two words... still it is a cool approach too.

<div>Name Surname</div>

div {
  box-sizing: border-box;
  display: inline-block;
  font-family: monospace;
  font-size: 1rem;
  height: 1rem;
  overflow: hidden;
  padding-top: 1rem;
  text-shadow: -5ch -1rem, 8ch -1rem;

You can see a demo of all of them on CodePen:


Oh damn! That box Shadow solution is pretty damn impressive!


Ruby Language

Robust version and with test specs!

def name_shuffler name
  name.to_s.strip.split(/\s+/).reverse.join(" ")

require "spec"

describe "#name_shuffler" do
  it { expect(name_shuffler "Foo Bar").to eq "Bar Foo"}
  it { expect(name_shuffler "Foo    Bar").to eq "Bar Foo"}
  it { expect(name_shuffler "   Foo Bar").to eq "Bar Foo"}
  it { expect(name_shuffler "Foo Bar   ").to eq "Bar Foo"}
  it { expect(name_shuffler "Foo").to eq "Foo"}
  it { expect(name_shuffler "   Foo").to eq "Foo"}
  it { expect(name_shuffler "Foo   ").to eq "Foo"}
  it { expect(name_shuffler "").to eq ""}
  it { expect(name_shuffler nil).to eq ""}
  it { expect(name_shuffler 777).to eq "777"}


>> rspec name_shuffler.rb

Finished in 0.0059 seconds (files took 0.15188 seconds to load)
10 examples, 0 failures
const nameShuffle = name => name.replace(/(\S+)\s(\S+)/, '$2 $1')

Rust Playground

fn name_shuffler(name: &str) -> String {
    name.split_whitespace().rev().collect::<Vec<&str>>().join(" ")

Buffer goes buf-buf

const rename = name => {
    const inBuf = Buffer.from(name, 'utf8')
    const len = inBuf.length
    const outBuf = Buffer.alloc(len, 0x20)
    let prev = 0
  for (let i = 0; i < len; i++) {
    if (inBuf[i] !== 0x20) continue
    inBuf.copy(outBuf, len - i, prev, i)
    prev = i + 1
  inBuf.copy(outBuf, 0, prev)
    return outBuf.toString('utf8')

Just because I'm lazy

const nameShuffler = (name) => {

  const [first, last] = [...name.split(' ')]

  return `${last} ${first}`



def name_shuffler(str)
  str.split(" ").reverse.join(" ")

It may not work if more than 2 names are provided, but hey:

const swap = (name) => {
  const [first, last] = name.split` `;
  return `${last} ${first}`;

Nice and simple python implementation 😁

def nameShuffler(name):
    name = name.split()

Here is the simple solution with Python:

def name_shuffler(string):
    string_array = string.split(' ')

    return string_array[1] + ' ' + string_array[0]

I think I may have gone overboard with the ol' backslashes for escaping, but...

sed 's/\s*\([^ ]\+\)\s\+\([^ ]\+\)\s*/\2 \1/' <<<"  Emma McClean"

My solution in js

const nameShuffler = (name) => `${name}`.split(' ').reverse().join(' ');


probably a terrible practice but that's how I'd do it

const nameShuffler = name => name.split(' ')[1] + ' ' + name.split(' ')[0]

ruby 2.7

def nameShuffler(s)
  s |> split ' ', 2 |> then { "#@2 #@1" }
p nameShuffler('Emma McClane')

Python :

def name_shuffler(name): return ' '.join([name.split()[1], name.split()[0]])


function nameShuffler(str){
  return str.split(' ').reverse().join(" ");
nameShuffler = unwords . reverse . words

Seems pretty simple (Haskell)


 echo implode(' ', array_reverse(explode(' ', $argv[1])));

There is my python solution