<?phpheader('Content-Type:text/html;charset=utf-8');functioncutstr($str,$len){if($len<0){returnnull;}$chars=0;//字符数量$offset=0;$res='';while($chars<$len){$high=decbin(ord(substr($str,$offset,1)));if(strlen($high)<8){$count=1;}elseif(substr($high,0,3)=='110'){$count=2;}elseif(substr($high,0,4)=='1110'){$count=3;}echo$count.'<br/>';$res.=substr($str,$offset,$count);$chars+=1;$offset+=$count;}return$res;}$str='你好aaaaa';echocutstr($str,2);?>