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());
    }
}      

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;
}

另一个改进:

/**
* Converts an array to XML
*
* @param array $array
* @param SimpleXMLElement $xml
* @param string $child_name
*
* @return SimpleXMLElement $xml
*/
public function arrayToXML($array, SimpleXMLElement $xml, $child_name)
{
    foreach ($array as $k => $v) {
        if(is_array($v)) {
            (is_int($k)) ? $this->arrayToXML($v, $xml->addChild($child_name), $v) : $this->arrayToXML($v, $xml->addChild(strtolower($k)), $child_name);
        } else {
            (is_int($k)) ? $xml->addChild($child_name, $v) : $xml->addChild(strtolower($k), $v);
        }
    }

    return $xml->asXML();
}

用法:

$this->arrayToXML($array, new SimpleXMLElement('<root/>'), 'child_name_to_replace_numeric_integers');

function array2xml(array $data, SimpleXMLElement $object = null, $oldNodeName = 'item')
{
    if (is_null($object)) $object = new SimpleXMLElement('<root/>');
    $isNumbered = true;
    $idx = 0;
    foreach ($data as $key => $x)
        if (is_string($key) || ($idx++ != $key + 0))
            $isNumbered = false;
    foreach ($data as $key => $value)
    {   
        $attribute = preg_match('/^[0-9]/', $key . '') ? $key : null;
        $key = (is_string($key) && !preg_match('/^[0-9]/', $key . '')) ? $key : preg_replace('/s$/', '', $oldNodeName);
        if (is_array($value))
        {
            $new_object = $object->addChild($key);
            if (!$isNumbered && !is_null($attribute)) $new_object->addAttribute('id', $attribute);
            array2xml($value, $new_object, $key);
        }
        else
        {
            if (is_bool($value)) $value = $value ? 'true' : 'false';
            $node = $object->addChild($key, htmlspecialchars($value));
            if (!$isNumbered && !is_null($attribute) && !isset($node->attributes()->id))
                $node->addAttribute('id', $attribute);
        }
    }
    return $object;
}

例如，该函数返回一个<obj>…</obj><obj>…</obj>数值索引的XML标记。

输入:

    array(
    'people' => array(
        'dog',
        'cat',
        'life' => array(
            'gum',
            'shoe',
        ),
        'fish',
    ),
    array('yeah'),
)

输出:

<root>
    <people>
        <people>dog</people>
        <people>cat</people>
        <life>
            <life>gum</life>
            <life>shoe</life>
        </life>
        <people>fish</people>
        <people>
            <people>yeah</people>
        </people>
    </people>
</root>

这应该能满足所有的共同需求。也许你可以把第三行改成:

$key = is_string($key) ? $key : $oldNodeName . '_' . $key;

或者如果你正在处理以s结尾的复数:

$key = is_string($key) ? $key : preg_replace('/s$/', '', $oldNodeName);

这里有一个函数帮我解决了这个问题:

就像这样叫它

echo arrayToXml("response",$arrayIWantToConvert);
function arrayToXml($thisNodeName,$input){
        if(is_numeric($thisNodeName))
            throw new Exception("cannot parse into xml. remainder :".print_r($input,true));
        if(!(is_array($input) || is_object($input))){
            return "<$thisNodeName>$input</$thisNodeName>";
        }
        else{
            $newNode="<$thisNodeName>";
            foreach($input as $key=>$value){
                if(is_numeric($key))
                    $key=substr($thisNodeName,0,strlen($thisNodeName)-1);
                $newNode.=arrayToXml3($key,$value);
            }
            $newNode.="</$thisNodeName>";
            return $newNode;
        }
    }

下面讨论名称空间。在本例中，构造包装器以包含名称空间定义，并将其传递给函数。使用冒号来标识命名空间。

测试数组

$inarray = [];
$inarray['p:apple'] = "red";
$inarray['p:pear'] = "green";
$inarray['p:peach'] = "orange";
$inarray['p1:grocers'] = ['p1:local' => "cheap", 'p1:imported' => "expensive"];


$xml = new SimpleXMLElement( '<p:wrapper xmlns:p="http://namespace.org/api" xmlns:p1="http://namespace.org/api2 /> ');

array_to_xml($xml,$inarray); 




function array_to_xml(SimpleXMLElement $object, array $data)
{   
    $nslist = $object->getDocNamespaces();

    foreach ($data as $key => $value)
    {   
        $nspace = null;
        $keyparts = explode(":",$key,2);
        if ( count($keyparts)==2) 
            $nspace = $nslist[$keyparts[0]];

        if (is_array($value))
        {   
            $key = is_numeric($key) ? "item$key" : $key;
            $new_object = $object->addChild($key,null,$nspace);
            array_to_xml($new_object, $value);
        }   
        else
        {   
            $key = is_numeric($key) ? "item$key" : $key;
            $object->addChild($key, $value,$nspace);
        }   
    }   
}