php中截取中文字符串

截取GB2312中文字符串

functionmysubstr($str,$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;
}

截取utf8编码的多字节字符串

functionutf8Substr($str,$from,$len){
returnpreg_replace('#^(?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'.$from.'}'.'((?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'.$len.'}).*#s','$1',$str);
}

UTF-8、GB2312都支持的汉字截取函数

functioncut_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>$sublen)returnjoin('',array_slice($t_string[0],$start,$sublen))."...";
returnjoin('',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;
}
}
$str="abcd需要截取的字符串";
echocut_str($str,8,0,'gb2312');

BugFree 的字符截取函数

functionsysSubStr($String,$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="ytecn.com豫唐网络";
$Length="18";
$Append=false;
echosysSubStr($String,$Length,$Append);