example-09.js

"use strict";

var leakedNodes = [],
  parentDiv,
  leaf,
  counter = 0;

function createLeaf() {
  counter++;
  var div = document.createElement("div");
  div.appendChild(document.createTextNode("Leaf  " + counter));
  div.someText = new Array(1e6).join("x");
  return div;
}

function createBranch(number) {
  var div = document.createElement("div");
  createNodesAndReturnLastLeaf(div, number - 1);
  return div;
}

function createNodesAndReturnLastLeaf(parentDiv, number) {
  var i, lastLeaf;
  for (i = 0; i < number; i++) {
    parentDiv.appendChild(createBranch(number));
  }
  for (i = 0; i < number; i++) {
    parentDiv.appendChild((lastLeaf = createLeaf(number, i)));
  }
  return lastLeaf;
}

function createTree() {
  parentDiv = document.createElement("div");
  leaf = createNodesAndReturnLastLeaf(parentDiv, 4);
  document.body.appendChild(parentDiv);
}

function detachTree() {
  document.body.removeChild(parentDiv);
}

function removeTreeReference() {
  parentDiv = null;
}

function removeLeafReference() {
  leaf = null;
}