The isConnected of Node for JS returns true if node is connected; otherwise false.
node.isConnected
baseURI
childNodes
cloneNode
compareDocumentPosition
contains
firstChild
getRootNode
hasChildNodes
isEqualNode
lastChild
nextSibling
nodeName
nodeType
normalize
ownerDocument
parentElement
parentNode
previousSibling
Web Hypertext Application Technology Working Group (WHATWG)
