php xml 和 数组 互转

第一种：

function buildXml( $data, $wrap= 'xml' ){
    $str = "<{$wrap}>";
    if( is_array( $data ) ){
         if( hasIndex( $data ) ){        
            foreach( $data as $k=>$v ){
                 $str .= buildXml( $v, $k );
            }
         }else{
            foreach( $data as $v ){
                foreach( $v as $k1=>$v1 )  
                $str .= buildXml( $v1, $k1 );
            }
         }
    }else{
		//$str .= $data;	
		$str.="<![CDATA[".$data."]]>";
	}
    $str .= "</{$wrap}>";
    return $str;
}

function hasIndex( $arr ){
    return array_keys($arr) !== range(0, count($arr) - 1);
}
$arr1 = [
    'title'=>'title',
    'bbb'=>[
        'AAA'=>12,
        'BBB'=>555
    ]
];
$arr2 = [
    'aaa'=>1,
    'bbb'=>[
        ['AAA'=>[
            'BBB'=>[
                ['DDDD'=>111],['DDDD'=>222]
            ]        
        ]],
        ['AAA'=>6]
    ]
];
header("Content-type: text/xml");
echo '<?xml version="1.0" encoding="utf-8"?>';
echo buildXml($arr1);
exit;

//数组转XML    第二种：
    function arrayToXml($arr)
    {
        $xml = "<xml>";
        foreach ($arr as $key=>$val)
        {
            if (is_numeric($val)){
                $xml.="<".$key.">".$val."</".$key.">";
            }else{
                 $xml.="<".$key."><![CDATA[".$val."]]></".$key.">";
            }
        }
        $xml.="</xml>";
        return $xml;
    }
 
  

  //将XML转为array
    function xmlToArray($xml)
    {   
        //禁止引用外部xml实体
        libxml_disable_entity_loader(true);
        $values = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true);       
        return $values;
    }