var elem = document.getElementById(‘elem_id’);
hello world var text\_node = div.firstChild; var text\_node = document.createTextNode(text);
<div id='mydiv'><!-- comment --></div> var mydiv = document.getElementById('mydiv'); var comment = mydiv.firstChild; var comment = document.createComment('comment');
elem.attributes中的节点 var attr = document.createAttribute(attr_name);