Run results for: ac4a526a-71a7-4ee8-a9eb-3df388fff075

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.96 Safari/537.36 Edg/88.0.705.56

Browser: Chrome 88

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
isInDOM1	984583.6 Ops/sec
isInDOM2	2004449.1 Ops/sec
isInDOM3	745399.5 Ops/sec

HTML Preparation code:

<div id="test-div"></div>

Script Preparation code:

function isInDOM1(oHTMLElement) {                                   
  if (oHTMLElement === document.body || oHTMLElement === document ) {
    return true;
  } else {
    try {
      return document.body.contains(oHTMLElement);
    } catch(ex) {
      // Sometimes in Firefox element is anonymous div around input.
      // Throws error "TypeError: Argument 1 of Node.contains does not implement interface Node"
      // See https://bugzilla.mozilla.org/show_bug.cgi?id=208427
      return false;
    }
  }
}

function isInDOM2(oHTMLElement) {                                   
  var root = oHTMLElement.ownerDocument; 
  if (!root) { return false; }
  
  if ( oHTMLElement.ownerDocument.documentElement === document.documentElement ){ return true; }

  return false;
}

function isInDOM3(oHTMLElement) {
  var node = oHTMLElement;
  var documentRoot = document.body.getRootNode();
  while (node.parentNode !== documentRoot && node.parentNode !== undefined && node.parentNode !== null)
    node = node.parentNode;
  
  return node.parentNode === documentRoot;
}

var div = document.getElementById('test-div');

Tests:

isInDOM1
isInDOM1(div);
isInDOM2
isInDOM2(div);
isInDOM3
isInDOM3(div);

Run results for: ac4a526a-71a7-4ee8-a9eb-3df388fff075

Check if given element is in dom

isInDOM1

isInDOM2

isInDOM3