Reorder html elements in dom

Keep in mind that when you add an element that is already in the DOM, this element will be moved, not copied.

CodePen

let wrapper=document.querySelector(".wrapper");
let children=wrapper.children;
let newOrder=[3,2,1,0];
//it means that the first element you want it to be the four element
//The second element you want it to be the third
//the third element you want it to be the second
//the four element you want it to be the first
for(let i=0;i<newOrder.length;i++){
  for(let j=0;j<newOrder.length;j++){
    if(i==newOrder[j]){
      wrapper.appendChild(children[j]);
      break;
    }
  }
}

<div class="wrapper">
  <div>a</div>
  <div>b</div>
  <div>c</div>
  <div>d</div>
</div>

I know this is an old question, but google lead me to it. There is a sub property on flexbox (css) called 'order', that allow you to choose the order that elements are displayed. Is possible to use javascript to change this sub property and reorder the displayed elements.

https://www.w3schools.com/cssref/css3_pr_order.asp

Edit 1 - code example:

<style>
 .wrapper {
   display: flex;
   flex-flow: column;
 }
</style>

<div class="wrapper">
  <div class="abc">One</div>
  <div class="abc">Tow</div>
  <div class="abc">Three</div>
</div>
<button id="reorder" type="button">Reorder</button>
<button id="unreorder" type="button">Unreorder</button>

<script>
var reorderButton = document.querySelector('#reorder');
var unreorderButton = document.querySelector('#unreorder');
var abcDivs = document.querySelectorAll('.abc');
var newOrder = [2, 1, 0];

reorderButton.addEventListener('click', function() {
  abcDivs.forEach(function(element, index) {
    element.style.order = newOrder[index];
  });
});
unreorderButton.addEventListener('click', function() {
  abcDivs.forEach(function(element, index) {
    element.style.order = null;
  });
});
</script>

no need to copy all items .. twice

var wrapper = $('.wrapper'), 
    items = wrapper.children('.abc'),
    arr = [2,1,0];

//items.detach(); if arr doesn't reuse all items
wrapper.append( $.map(arr, function(v){ return items[v] }) );

If you want a pure Javascript solution (no jQuery involved)

var arr = [2,1,0];
var wrapper = document.getElementsByClassName("wrapper");
var items = wrapper[0].children;
var elements = document.createDocumentFragment();

arr.forEach(function(idx) {
    elements.appendChild(items[idx].cloneNode(true));
});

wrapper[0].innerHTML = null;
wrapper[0].appendChild(elements);

A little improvement of my previous answer. Fiddle: https://jsfiddle.net/jltorresm/1ukhzbg2/2/