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Daily Challenge #37 - Name Swap

dev.to staff on August 09, 2019

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...

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Fernando Doglio • Aug 9 '19

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(" ")
}

Ju 🔗 • Aug 9 '19

And with arrow function

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

Fernando Doglio • Aug 9 '19

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

Alvaro Montoro • Aug 9 '19 • Edited

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:

Corey Alexander • Aug 9 '19

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

Michael Lang • Aug 9 '19 • Edited

Ruby Language

Robust version and with test specs!

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

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"}
end

output

>> rspec name_shuffler.rb
..........

Finished in 0.0059 seconds (files took 0.15188 seconds to load)
10 examples, 0 failures

kip • Aug 9 '19

const nameShuffle = name => name.replace(/(\S+)\s(\S+)/, '$2 $1')

Mihail Malo • Aug 11 '19

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')
}

𝚃𝚒𝚊𝚐𝚘 𝙲𝚘𝚜𝚝𝚊 • Aug 9 '19

def nameShuffler(fullname: str) -> str:
    return ' '.join(fullname.split()[::-1])

𝚃𝚒𝚊𝚐𝚘 𝙲𝚘𝚜𝚝𝚊 • Aug 9 '19

Python version using static typing features.

Jay • Aug 9 '19

Rust Playground

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

Alexander Garcia • Aug 9 '19

Just because I'm lazy

const nameShuffler = (name) => {

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

  return `${last} ${first}`

}

La blatte • Aug 9 '19

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

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

Jeremy Schuurmans • Aug 9 '19

Ruby!

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

Ben Sinclair • Aug 9 '19

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

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

Henry 👨‍💻 • Aug 10 '19 • Edited

Nice and simple python implementation 😁

def nameShuffler(name):
    name = name.split()
    name.reverse()
    print(str(name))

official_dulin • Sep 9 '20

JavaScript:

function nameShuffler(str){
  return str.split(' ').reverse().join(" ");
}

peter279k • Jun 19 '20

Here is the simple solution with Python:

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

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

K.V.Harish • Oct 3 '19

My solution in js


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

Alexander P. • Aug 9 '19

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

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

Seiei Miyagi • Aug 9 '19

ruby 2.7

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

Miguel Ángel Sánchez Chordi • Aug 13 '19

 <?php

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

Héctor Pascual • Aug 13 '19 • Edited

Python :

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

Craig McIlwrath • Aug 21 '19

nameShuffler = unwords . reverse . words

Seems pretty simple (Haskell)

diek • Aug 10 '19

There is my python solution