以上答案大部分是正确的。然而，我想出了这个答案，它解决了array_walk_recursive的兼容性问题，也解决了数值键的问题。它也通过了我做的所有测试:

function arrayToXML(Array $array, SimpleXMLElement &$xml) {

    foreach($array as $key => $value) {

        // None array
        if (!is_array($value)) {
            (is_numeric($key)) ? $xml->addChild("item$key", $value) : $xml->addChild($key, $value);
            continue;
        }   

        // Array
        $xmlChild = (is_numeric($key)) ? $xml->addChild("item$key") : $xml->addChild($key);
        arrayToXML($value, $xmlChild);
    }
}   

我还为此添加了一个测试类，你可能会发现有用:

class ArrayToXmlTest extends PHPUnit_Framework_TestCase {

    public function setUp(){ }
    public function tearDown(){ }

    public function testFuncExists() {
        $this->assertTrue(function_exists('arrayToXML'));
    }

    public function testFuncReturnsXml() {
        $array = array(
            'name' => 'ardi',
            'last_name' => 'eshghi',
            'age' => 31,
            'tel' => '0785323435'
        );

        $xmlEl =  new SimpleXMLElement('<root/>');
        arrayToXml($array, $xmlEl);

        $this->assertTrue($xmlEl instanceOf SimpleXMLElement);
    }

    public function testAssocArrayToXml() {

        $array = array(
            'name' => 'ardi',
            'last_name' => 'eshghi',
            'age' => 31,
            'tel' => '0785323435'
        );

        $expectedXmlEl = new SimpleXMLElement('<root/>'); 
        $expectedXmlEl->addChild('name', $array['name']);
        $expectedXmlEl->addChild('last_name', $array['last_name']);
        $expectedXmlEl->addChild('age', $array['age']);
        $expectedXmlEl->addChild('tel', $array['tel']);

        $actualXmlEl =  new SimpleXMLElement('<root/>');
        arrayToXml($array, $actualXmlEl);

        $this->assertEquals($expectedXmlEl->asXML(), $actualXmlEl->asXML());
    }

    public function testNoneAssocArrayToXml() {

        $array = array(
            'ardi',
            'eshghi',
            31,
            '0785323435'
        );

        // Expected xml value
        $expectedXmlEl = new SimpleXMLElement('<root/>'); 
        foreach($array as $key => $value)
            $expectedXmlEl->addChild("item$key", $value);

        // What the function produces       
        $actualXmlEl =  new SimpleXMLElement('<root/>');
        arrayToXml($array, $actualXmlEl);

        $this->assertEquals($expectedXmlEl->asXML(), $actualXmlEl->asXML());
    }

    public function testNestedMixArrayToXml() {

        $testArray = array(
            "goal",
            "nice",
            "funny" => array(
                'name' => 'ardi',
                'tel'   =>'07415517499',
                "vary",
                "fields" => array(
                    'small',
                    'email' => 'ardi.eshghi@gmail.com'
                ),

                'good old days'

            ),

            "notes" => "come on lads lets enjoy this",
            "cast" => array(
                'Tom Cruise',
                'Thomas Muller' => array('age' => 24)
            )
        );

        // Expected xml value
        $expectedXmlEl = new SimpleXMLElement('<root/>'); 
        $expectedXmlEl->addChild('item0', $testArray[0]);
        $expectedXmlEl->addChild('item1', $testArray[1]);
        $childEl = $expectedXmlEl->addChild('funny');
        $childEl->addChild("name", $testArray['funny']['name']);
        $childEl->addChild("tel", $testArray['funny']['tel']);
        $childEl->addChild("item0", "vary");
        $childChildEl = $childEl->addChild("fields");
        $childChildEl->addChild('item0', 'small');
        $childChildEl->addChild('email', $testArray['funny']['fields']['email']);
        $childEl->addChild("item1", 'good old days');
        $expectedXmlEl->addChild('notes', $testArray['notes']);
        $childEl2 = $expectedXmlEl->addChild('cast');
        $childEl2->addChild('item0', 'Tom Cruise');
        $childChildEl2 = $childEl2->addChild('Thomas Muller');
        $childChildEl2->addChild('age', $testArray['cast']['Thomas Muller']['age']);

        // What the function produces       
        $actualXmlEl = new SimpleXMLElement('<root/>');
        arrayToXml($testArray, $actualXmlEl);

        $this->assertEquals($expectedXmlEl->asXML(), $actualXmlEl->asXML());
    }
}      

如果你使用magento，你有这种类型的关联数组

$test_array = array (
    '0' => array (
            'category_id' => '582',
            'name' => 'Surat',
            'parent_id' => '565',
            'child_id' => '567',
            'active' => '1',
            'level' => '6',
            'position' => '17'
    ),

    '1' => array (
            'category_id' => '567', 
            'name' => 'test',
            'parent_id' => '0',
            'child_id' => '576',
            'active' => '0',
            'level' => '0',
            'position' => '18'
    ),
);

那么最好将关联数组转换为XML格式。在控制器文件中使用此代码。

$this->loadLayout(false);
//header ("content-type: text/xml");
$this->getResponse()->setHeader('Content-Type','text/xml');
$this->renderLayout();

$clArr2xml = new arr2xml($test_array, 'utf-8', 'listdata');
$output = $clArr2xml->get_xml();
print $output; 

class arr2xml
{
var $array = array();
var $xml = '';
var $root_name = '';
var $charset = '';

public function __construct($array, $charset = 'utf-8', $root_name = 'root')
{
    header ("content-type: text/xml");
    $this->array = $array;
    $this->root_name = $root_name;
    $this->charset = $charset;

    if (is_array($array) && count($array) > 0) {
        $this->struct_xml($array);

    } else {
        $this->xml .= "no data";
    }
}

public function struct_xml($array)
{
    foreach ($array as $k => $v) {
        if (is_array($v)) {
            $tag = ereg_replace('^[0-9]{1,}', 'item', $k); // replace numeric key in array to 'data'
            $this->xml .= "<$tag>";
            $this->struct_xml($v);
            $this->xml .= "</$tag>";
        } else {
            $tag = ereg_replace('^[0-9]{1,}', 'item', $k); // replace numeric key in array to 'data'
            $this->xml .= "<$tag><![CDATA[$v]]></$tag>";
        }
    }
}

public function get_xml()
{

    $header = "<?xml version=\"1.0\" encoding=\"" . $this->charset . "\"?><" . $this->root_name . ">";
    $footer = "</" . $this->root_name . ">";

    return $header . $this->xml . $footer;
}
}

我希望这对大家都有帮助。

function toXML($data, $obj = false, $dom) {
    $is_first_level = false;
    if($obj === false) {
        $dom = new DomDocument('1.0');
        $obj = $dom;
        $is_first_level = true;
    }

    if(is_array($data)) {
        foreach($data as $key => $item) {
            $this->toXML($item, $obj->appendChild($dom->createElement($key)), $dom);
        }
    }else {
        $obj->appendChild($dom->createTextNode($data));
    }

    if($is_first_level) {
        $obj->formatOutput = true;
        return $obj->saveXML();
    }
    return $obj;
}

只是对上面的函数进行了编辑，当键是数字时，添加前缀“key_”

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

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

// 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 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{
                $subnode = $xml_student_info->addChild("key_$key");
                array_to_xml($value, $subnode);
            }
          }
          else {
               if(!is_numeric($key)){
                    $xml_student_info->addChild("$key","$value");
               }else{
                    $xml_student_info->addChild("key_$key","$value");
               }
          }
     }
}

<?php
function array_to_xml(array $arr, SimpleXMLElement $xml)
{
    foreach ($arr as $k => $v) {
        is_array($v)
            ? array_to_xml($v, $xml->addChild($k))
            : $xml->addChild($k, $v);
    }
    return $xml;
}

$test_array = array (
    'bla' => 'blub',
    'foo' => 'bar',
    'another_array' => array (
        'stack' => 'overflow',
    ),
);

echo array_to_xml($test_array, new SimpleXMLElement('<root/>'))->asXML();

您可以使用我一直在研究的XMLParser。

$xml = XMLParser::encode(array(
    'bla' => 'blub',
    'foo' => 'bar',
    'another_array' => array (
        'stack' => 'overflow',
    )
));
// @$xml instanceof SimpleXMLElement
echo $xml->asXML();

会导致:

<?xml version="1.0"?>
<root>
    <bla>blub</bla>
    <foo>bar</foo>
    <another_array>
        <stack>overflow</stack>
    </another_array>
</root>