PHP截取字符串专题

1. 截取GB2312中文字符串

<?php< ?php //截取中文字符串function mysubstr($str, $start, $len) { $tmpstr = ''; $strlen = $start + $len; for($i = 0; $i < $strlen; $i++) { if(ord(substr($str, $i, 1)) > 0xa0) { $tmpstr .= substr($str, $i, 2); $i++; } else $tmpstr .= substr($str, $i, 1); } return $tmpstr;}?>

2. 截取utf8编码的多字节字符串

<?php< ?php//截取utf8字符串function utf8Substr($str, $from, $len){ return preg_replace('#^(?:[x00-x7F]|[xC0-xFF][x80-xBF]+){0,'.$from.'}'. '((?:[x00-x7F]|[xC0-xFF][x80-xBF]+){0,'.$len.'}).*#s', '$1',$str);}?>3. UTF-8、GB2312都支持的汉字截取函数

<?php< ?php/* Utf-8、gb2312都支持的汉字截取函数 cut_str(字符串, 截取长度, 开始长度, 编码); 编码默认为 utf-8 开始长度默认为 0 */ function cut_str($string, $sublen, $start = 0, $code = 'UTF-8') { if($code == 'UTF-8') { $pa = '/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/'; preg_match_all($pa, $string, $t_string); if(count($t_string[0]) - $start > $sublen) return join('', array_slice($t_string[0], $start, $sublen)).'...'; return join('', array_slice($t_string[0], $start, $sublen)); } else { $start = $start*2; $sublen = $sublen*2; $strlen = strlen($string); $tmpstr = ''; for($i=0; $i< $strlen; $i++) { if($i>=$start && $i< ($start+$sublen)) { if(ord(substr($string, $i, 1))>129) { $tmpstr.= substr($string, $i, 2); } else { $tmpstr.= substr($string, $i, 1); } } if(ord(substr($string, $i, 1))>129) $i++; } if(strlen($tmpstr)< $strlen ) $tmpstr.= '...'; return $tmpstr; } } $str = 'abcd需要截取的字符串'; echo cut_str($str, 8, 0, 'gb2312'); ?>4. BugFree 的字符截取函数

<?php< ?php /** * @package;;BugFree * @version;;$Id: FunctionsMain.inc.php,v 1.32 2005/09/24 11:38:37 wwccss Exp $ * * * Return part of a string(Enhance the function substr()) * * @author; Chunsheng Wang <wwccss@263.net> * @param string; $String; the string to cut. * @param int;;$Length; the length of returned string. * @param booble; $Append; whether append '...': false|true * @return stringthe cutted string. */ function sysSubStr($String,$Length,$Append = false) { if (strlen($String) < = $Length ) { return $String; } else { $I = 0; while ($I < $Length) { $StringTMP = substr($String,$I,1); if ( ord($StringTMP) >=224 ) { $StringTMP = substr($String,$I,3); $I = $I + 3; } elseif( ord($StringTMP) >=192 ) { $StringTMP = substr($String,$I,2); $I = $I + 2; } else { $I = $I + 1; } $StringLast[] = $StringTMP; } $StringLast = implode('',$StringLast); if($Append) { $StringLast .= '...'; } return $StringLast; } } $String = 'CodeBit.cn -- 简单、精彩、通用'; $Length = '18'; $Append = false; echo sysSubStr($String,$Length,$Append); ?>