Sleep Sort

Written 4 weeks ago

Behold

const arr = [1, 5, 9, 7, 2, 8, 4, 3, 6]
arr.forEach((x) => setTimeout(() => console.log(x), x * 1000))
// Output: 1, 2, 3, 4, 5, 6, 7, 8, 9

Try it yourself, open a browser console window and paste this code!

What sorcery is this?

Reveal the secrets!

More resources for the curious

• Reddit Link for code inspiration

• AlgorithmByExamples | Python

Bonus Example

Here’s a go code example, just for kicks:

package main

import (
	"fmt"
	"sync"
	"time"
)

func main() {
	var wg sync.WaitGroup
	arr := []int{1, 5, 9, 7, 2, 8, 4, 3, 6}

	for _, n := range arr {
		wg.Add(1)
		go (func() {
			time.Sleep(time.Duration(n) * time.Second)
			fmt.Println(n)
			wg.Done()
		})()
	}

	wg.Wait()
	fmt.Println("Voila!")
}

and another in bash, probably where “sleep” originated:

#!/usr/bin/env bash

arr=(1 5 9 7 2 8 4 3 6)

for i in ${arr[*]}; do
  sleep $i && echo $i &
done

wait
echo "Voila!"