The XMLReader::lookupNamespace() function is an inbuilt function in PHP which is used to lookup in scope namespace for a given prefix.
Syntax:
string XMLReader::lookupNamespace( string $prefix )
Parameters: This function accepts a single parameter $prefix which holds the string containing the prefix.
Return Value: This function returns TRUE on success or FALSE on failure.
Below given programs illustrate the XMLReader::lookupNamespace() function in PHP:
Program 1:
Filename: data.xml
<?xml version="1.0" encoding="utf-8"?> <div xmlns:z="my_namespace"> Â Â Â Â <z:h1 z:attrib="value"> Foo Bar </z:h1> </div> |
Filename: index.php
<?php   // Create a new XMLReader instance $XMLReader = new XMLReader();   // Open the XML file $XMLReader->open('data.xml');   // Read the node $XMLReader->read();   // Get the namespace with prefix y $NS = $XMLReader->lookupNamespace("y");   // Show the namespace to browser echo $NS; ?> |
Output:
// Empty string because there is no namespace with prefix y.
Program 2:
Filename: data.xml
<?xml version="1.0" encoding="utf-8"?> <div xmlns:x="neveropen"> Â Â Â Â <x:h1 x:attrib="value"> Namespaced Text </x:h1> </div> |
Filename: index.php
<?php   // Create a new XMLReader instance $XMLReader = new XMLReader();   // Open the XML file $XMLReader->open('data.xml');   // Read the node $XMLReader->read();   // Get the namespace with prefix x $NS = $XMLReader->lookupNamespace("x");   // Show the namespace to browser echo $NS; ?> |
Output:
neveropen
Reference: https://www.php.net/manual/en/xmlreader.lookupnamespace.php
