您也可以通过DOM来实现这一点。请参阅下面的代码。

<?php

$el = array();
$command = array();

$dom = new DOMDocument('1.0', 'utf-8');
$dom->formatOutput = true;

$xml_array = [
    'root'=>[
    'Good guy' => [
        'name' => [
            '_cdata' => 'Luke Skywalker'
        ],
        'weapon' => 'Lightsaber'
    ],
    'Bad guy' => [
        'name' => 'Sauron',
        'weapon' => 'Evil Eye'
    ]
        ]
];

convert_xml($xml_array);

if(!empty($el))
{
    $dom->appendChild(end($el));
}

echo $dom->saveXML();

?>

<?php

 function convert_xml($Xml)
{
    global $el, $dom;

        foreach($Xml as $id=>$val)
        {
            if(is_numeric($id))
            {
                $id = "Item".($id);
            }

            $id = str_replace(' ', '-', strtolower($id));

            if(is_array($val))
            {
                $ele = $dom->createElement($id);
                array_push($el, $ele);
                convert_xml($val);
            }
            else
            {
                $ele = $dom->createElement($id, $val);

                if(!empty($el))
                {
                    $com = end($el)->appendChild($ele);
                }
                else
                {
                    $dom->appendChild($ele);
                }

            }
        }

        if(sizeof($el) > 1)
        {
            $child = end($el);
            $com = prev($el)->appendChild($child);
            array_pop($el);
        }
}

?>

我发现所有的答案都是使用过多的代码。这里有一个简单的方法:

function to_xml(SimpleXMLElement $object, array $data)
{   
    foreach ($data as $key => $value) {
        if (is_array($value)) {
            $new_object = $object->addChild($key);
            to_xml($new_object, $value);
        } else {
            // if the key is an integer, it needs text with it to actually work.
            if ($key != 0 && $key == (int) $key) {
                $key = "key_$key";
            }

            $object->addChild($key, $value);
        }   
    }   
}   

然后，将数组发送到使用递归的函数中就很简单了，因此它将处理多维数组:

$xml = new SimpleXMLElement('<rootTag/>');
to_xml($xml, $my_array);

现在$xml包含了一个漂亮的xml对象，它完全基于您编写数组的方式。

print $xml->asXML();

这是我的入口，简单而干净。

function array2xml($array, $xml = false){
    if($xml === false){
        $xml = new SimpleXMLElement('<root/>');
    }
    foreach($array as $key => $value){
        if(is_array($value)){
            array2xml($value, $xml->addChild($key));
        }else{
            $xml->addChild($key, $value);
        }
    }
    return $xml->asXML();
}


header('Content-type: text/xml');
print array2xml($array);

如果冗长的xml不成问题，可以使用xmlrpc_encode从数组创建xml。 www.php.net/xmlrpc_encode

注意，如果使用关联键和/或数字键，创建的XML会有所不同

<?php
// /params/param/value/struct/member
// there is a tag "member" for each element
// "member" contains a tag "name". its value is the associative key
$xml1 = xmlrpc_encode(array('a'=>'b','c'=>'d'));
$simplexml1 = simplexml_load_string($xml1);
print_r($xml1);
print_r($simplexml1);

// /params/param/value/array/data
// there is a tag "data" for each element
// "data" doesn't contain the tag "name"
$xml2 = xmlrpc_encode(array('a','b'));
$simplexml2 = simplexml_load_string($xml2);
print_r($xml2);
print_r($simplexml2);
?>

整个XML结构定义在$data数组中:

function array2Xml($data, $xml = null)
{
    if (is_null($xml)) {
        $xml = simplexml_load_string('<' . key($data) . '/>');
        $data = current($data);
        $return = true;
    }
    if (is_array($data)) {
        foreach ($data as $name => $value) {
            array2Xml($value, is_numeric($name) ? $xml : $xml->addChild($name));
        }
    } else {
        $xml->{0} = $data;
    }
    if (!empty($return)) {
        return $xml->asXML();
    }
}

来自PHP 5.4

function array2xml($data, $root = null){
    $xml = new SimpleXMLElement($root ? '<' . $root . '/>' : '<root/>');
    array_walk_recursive($data, function($value, $key)use($xml){
        $xml->addChild($key, $value);
    });
    return $xml->asXML();
}