random DOM nodes

randomdomnodes.js

var comments = document.querySelectorAll('#comment-list > li');
var commentsList = [];

var array = new Uint32Array(comments.length);
var randomIds = window.crypto.getRandomValues(array);

Array.prototype.forEach.call(comments, function(el, i){
  if (el.id) commentsList.push({id: el.id, rand: randomIds[i]});
});

commentsList.sort(function(a, b) {
  return a.rand - b.rand;
});

getWinnerComment = function(id) {
  return document.querySelectorAll('#' + id + ' .comment-content p')[0].textContent;
}

console.log(commentsList[0].id, getWinnerComment(commentsList[0].id));
console.log(commentsList[1].id, getWinnerComment(commentsList[1].id));
console.log(commentsList[2].id, getWinnerComment(commentsList[2].id));