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How to determine whether an element is an HTMLElement element_javascript tips

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Release： 2016-05-16 17:10:16
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We often use nodeType==1 to determine whether an element is an HMTLElement element. The elements on the page are all nodes, including Element Node, Attribute Node, Text Node, etc. The definition of w3c nodeType is as follows

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_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_FRAGMENT_NODE = 11;
const unsigned short NOTATION_NODE = 12;

But what if our custom object also contains the nodeType attribute? For example,



Copy code The code is as follows:
var obj = {nodeType:1};
function isHTMLElement(obj){
if(obj.nodeType){
return obj.nodeType==1;
}
}
isHTMLElement(obj);//true


The above isHTMLElement(obj) returns true, but obj is obviously not an HTML node element. The following is judged by object characteristics and try-catch statements.


Copy code The code is as follows:
function isHTMLElement(obj){
var d = document.createElement("div");
try{
d.appendChild(obj.cloneNode(true));
return obj.nodeType==1?true:false;
}catch( e){
            return false; document.createElement("p");
isHTMLElement(obj1);//false
isHTMLElement(obj2);//false
isHTMLElement(obj3);//true


Special treatment is required for window and document




Copy code


The code is as follows:
function isHtmlControl (obj) { var d = document.createElement("div"); try{ d.appendChild(obj.cloneNode(true));
return obj.nodeType= =1 ? true : false;
}catch(e){
} return obj==window || obj==document;
}
}


Related labels：
HTMLElement
source：php.cn
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