Example php 5.2 code to convert array of any depth to xml document:

Array
(
    [total_stud]=> 500
    [0] => Array
        (
            [student] => Array
                (
                    [id] => 1
                    [name] => abc
                    [address] => Array
                        (
                            [city]=>Pune
                            [zip]=>411006
                        )                       
                )
        )
    [1] => Array
        (
            [student] => Array
                (
                    [id] => 2
                    [name] => xyz
                    [address] => Array
                        (
                            [city]=>Mumbai
                            [zip]=>400906
                        )   
                )

        )
)

generated XML would be as:

    500
    
        1
        abc

            Pune
            411006
    
    
        1
        abc

            Mumbai
            400906
    

PHP snippet

<?php
// initializing or creating array
$student_info = array(your array data);

// creating object of SimpleXMLElement
$xml_student_info = new SimpleXMLElement('<?xml version="1.0"?>');

// function call to convert array to xml
array_to_xml($student,$xml_student_info);

//saving generated xml file
$xml_student_info->asXML("file path and name");

// function defination to convert array to xml
function array_to_xml($student_info, &$xml_student_info) {
    foreach($student_info as $key => $value) {
        if(is_array($value)) {
            if(!is_numeric($key)){
                $subnode = $xml_student_info->addChild("$key");
                array_to_xml($value, $subnode);
            }
            else{
                array_to_xml($value, $xml_student_info);
            }
        }
        else {
            $xml_student_info->addChild("$key","$value");
        }
    }
}
?>