php截取字符串方法

对于英语字母比较好

 function cnsubstr($str,$strlen) { if(empty($str)||!is_numeric($strlen)){ return false; } if(strlen($str)<=$strlen){ return $str; } //得到第$length个字符 并判断是否为非中文 若为非中文 //直接返回$length长的字符串 $last_word_needed=substr($str,$strlen-1,1); if(!ord($last_word_needed)>128){ $needed_sub_sentence=substr($str,0,$strlen); return $needed_sub_sentence; }else{ for($i=0;$i<$strlen;$i++){ if(ord($str[$i])>128){ $i++; } }//end of for $needed_sub_sentence=substr($str,0,$i); return $needed_sub_sentence; } }

//对于utf—8字符比较好

function utf_substr($str,$len){for($i=0;$i<$len;$i++){$temp_str=substr($str,0,1);if(ord($temp_str) > 127){$i++;if($i<$len){$new_str[]=substr($str,0,3);$str=substr($str,3);}}else{$new_str[]=substr($str,0,1);$str=substr($str,1);}}return join($new_str);}