与java.String对比 [table] ||id|java.String|php.String| ||0| equals | strcmp | ||1| substring(start,end)| substr(string,start,length) | ||2| indexOf(str, fromIndex)| strpos stripos , strstr stristr strrpos| ||3| concat(str) (+)| (.)| ||4| startsWith || ||5| endsWith || ||6| getBytes | | ||7| matches | | ||8| replace | str_replace(find, replace, str, count) , str_ireplace| ||9| replaceAll || ||10| split | | ||11| toLowerCase | strtolower() | ||12| toUpperCase | strtoupper()| ||13| trim() | trim() ltrim() rtrim()| ||14| length | strlen | ||15| | md5| ||16| format|fprintf| [/table]

php join md5