XML DOM lookupPrefix() Method
❮ Node Object
Example
The following code fragment loads "books_ns.xml" into xmlDoc and finds the prefix for the given namespace URI:
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
   if (this.readyState == 4 && this.status == 200) {
       myFunction(this);
   }
};
xhttp.open("GET", "books_ns.xml", true);
xhttp.send();
function myFunction(xml) {
           var xmlDoc = xml.responseXML;
    var x = 
xmlDoc.getElementsByTagName("book")[0];
    
document.getElementById("demo").innerHTML =
    
x.lookupPrefix("https://www.w3schools.com/children/");
} 
Output:
c
Try it Yourself »
Definition and Usage
The lookupPrefix() method returns the prefix associated with a given namespace URI.
Browser Support
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The lookupPrefix() method is supported in all major browsers.
Note: Internet Explorer 9 and earlier does not support this method.
Syntax
nodeObject.lookupPrefix(namespaceURI)
Parameters
| Parameter | Type | Description | 
|---|---|---|
| namespaceURI | String | Required. Specifies the namespace URI to look for | 
Return Value
| Type | Description | 
|---|---|
| String | The prefix associated with the specified namespace URI | 
Technical Details
| DOM Version | Core Level 3 Node Object | 
|---|
❮ Node Object

