判断元素是否为HTMLElement元素【转载】
地址：http://www.cnblogs.com/snandy/archive/2011/03/12/1981516.html
我们经常使用nodeType==1判断元素是否是一个HMTLElement元素。页面上的元素都是节点(Node)，有元素节点(Element Node)、属性节点(Attribute Node)、文本节点(Text Node)等。w3c nodeType 的定义如下
const unsigned short ELEMENT_NODE = 1;
const unsigned short ATTRIBUTE_NODE = 2;
const unsigned short TEXT_NODE = 3;
const unsigned short CDATA_SECTION_NODE = 4;
const unsigned short ENTITY_REFERENCE_NODE = 5;
const unsigned short ENTITY_NODE = 6;
const unsigned short PROCESSING_INSTRUCTION_NODE = 7;
const unsigned short COMMENT_NODE = 8;
const unsigned short DOCUMENT_NODE = 9;
const unsigned short DOCUMENT_TYPE_NODE = 10;
const unsigned short DOCUMENT_FRAGMENT_NODE = 11;
const unsigned short NOTATION_NODE = 12;
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但如果我们自定义的对象也包含nodeType属性呢？如
view sourceprint?
1var obj = {nodeType:1}; 2function isHTMLElement(obj){ 3????if(obj.nodeType){ 4????????return obj.nodeType==1; 5????} 6} 7isHTMLElement(obj);//true以上isHTMLElement(obj)返回true，但obj明显不是一个HTML节点元素。下面通过对象特性及try-catch语句来判断。
view sourceprint?01function isHTMLElement(obj){ 02????var d = document.createElement("div"); 03????try{ 04????????d.appendChild(obj.cloneNode(true)); 05????????return obj.nodeType==1?true:false; 06????}catch(e){ 07????????return false; 08????} 09} 10var obj1 = {nodeType:1}; 11var obj2 = document.createTextNode("hello"); 12var obj2 = document.createElement("p"); 13isHTMLElement(obj1);//false 14isHTMLElement(obj2);//false 15isHTMLElement(obj3);//true对于window和document还要特别处理下
view sourceprint?01function isHtmlControl(obj) {? 02??03????var d = document.createElement("div"); 04????try{ 05????????d.appendChild(obj.cloneNode(true)); 06????????return obj.nodeType==1 ? true : false; 07????}catch(e){ 08????????return obj==window || obj==document; 09????} 10}??