fisher-yates shuffle

shuffle.js

// 4 June 2019
// fisher-yates shuffle
// array and array-like structures
// modified from very nice implementation at
// https://stackoverflow.com/questions/2450954/how-to-randomize-shuffle-a-javascript-array/2450976#2450976

function shuffle(items) {
  var array = Object.keys(items);
  var currentIndex = array.length, temporaryValue, randomIndex;

  // While there remain elements to shuffle...
  while (0 !== currentIndex) {

    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    // And swap it with the current element.
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }
  
  return items[array[Math.floor(Math.random() * currentIndex)]];
}

var tests = [
  [1,2,3,4,5,6,7,8],
  { 0: 'name', 1: 'value', 2: 'property', 3: 'attribute', 4: 'firstChild', 5: 'lastChild'}
];

var results = tests.map(function(test) {
  return shuffle(test);
});

console.log(JSON.stringify(results, null, 2));