The DOM: . 1 . Found label a direct find. Retrieve a single element document.getElementById ( ' I1 ' ) Looking (list) doucment.getElementsByTagName (by tag name ' div ' ) doucment.getElementsByClassName ( ' C1 ' ) B indirect to find. Tag = doucment.getElementById ( ' I1 ' ) parentElement # parent tag element Children # all sub tags firstElementChild # first child element tag lastElementChild # last child tag element nextElementtSibling # next sibling label element previousElementSibling # on a Brother label element 2 . Operation label a.innerText get text label tag .innerText label text reassigned (more tags need modified loop) labels .innerText = "" b.innerHTML if the mode re-label assignment, if the format of the content with the tag, label format will automatically be converted to HTML format, and then all innerText content directly into a string b.className tag.className # overall operation tag.classList.add ( ' style name ') # Adds the specified style tag.classList.remove ( ' the style name ' ) # delete the specified style c.checkbox get the value checkbox objects .checked settings checkbox objects .checked = to true (the operation of the selection box) 3 . Create a label document. the createElement ( " div " ); / * * need to tie to add nodes / 4 add nodes. 1 append a child node. d2.appendChild (new label) 2 see this increased front node into a node. parent node insertBefore. (want to add the new node before the node) 5 . delete node 6Alternatively Node 7. Get / Set Attribute node label .getAttribute ( " attribute name / type name " ) tab .setAttribute ( " attribute name / class name " , " new attribute " )