php判断str字符串是否是xml格式数据的方法示例

<?php//自定义xml验证函数xml_parser()function xml_parser($str){    $xml_parser = xml_parser_create();    if(!xml_parse($xml_parser,$str,true)){      xml_parser_free($xml_parser);      return false;    }else {      return (json_decode(json_encode(simplexml_load_string($str)),true));    }}//应用示例：$xmlstr=<<<ETO<?xml version="1.0" encoding="UTF-8"?><books>  <book>    <author>Jack Herrington</author>    <title>PHP Hacks</title>    <publisher>O'Reilly</publisher>  </book>  <book>    <author>Jack Herrington</author>    <title>Podcasting Hacks</title>    <publisher>O'Reilly</publisher>  </book>  <book>    <author>XML数据</author>    <title>VeVb武林网</title>    <publisher>tools.vevb.com</publisher>  </book></books>ETO;$jsonstr='{ "tools": [ { "name":"css format" , "site":"http://tools.vevb.com/code/css" }, { "name":"json format" , "site":"http://tools.vevb.com/code/json" }, { "name":"pwd check" , "site":"http://tools.vevb.com/password/my_password_safe" } ] }';if(xml_parser($xmlstr)){ echo "/$xmlstr是xml格式数据";}else{ echo "/$xmlstr不是xml格式数据";}echo "<br/>";if(xml_parser($jsonstr)){ echo "/$jsonstr是xml格式数据";}else{ echo "/$jsonstr不是xml格式数据";}?>

$xmlstr是xml格式数据$jsonstr不是xml格式数据