XML : How to convert xml string into array in php

  <?xml version="1.0" encoding="utf-8"?>  <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">    <soap:Body>      <CallTHIResponse xmlns="http://tempuri.org/">        <CallTHIResult>string</CallTHIResult>      </CallTHIResponse>    </soap:Body>  </soap:Envelope>    ***********************************************  CallTHIResult return value : <TRAN_ID>17560_41206.6291_9568</TRAN_ID><TRAN_DATE>20160128</TRAN_DATE><TRAN_TIME>11:26:46</TRAN_TIME><ERROR_CODE>1</ERROR_CODE><ERROR_DESC>Not Input Policy</ERROR_DESC><POLICY_NBR></POLICY_NBR><URL_POLICY>http://test.php/xxx.pdf</URL_POLICY>    

I can not get the value for array management into the fileds database.