php截取字符串的实例代码(支持utf-8)

分享下php中截取字符串的例子，支持utf-8格式。

1，截取字符串

<?php 
$string="2006年4月我又长大了一岁！"; 
echo substr($string,1)."..."; 
//截取字符串 
function SubstrGB($in,$num) 
{ 
$pos=0; 
$out=""; 
while($pos<strlen($in)) 
{ 
$c=substr($in,$pos,1); 
if($c=="
") break; 
if(ord($c)>128) 
{ 
$out.=$c; 
$pos++; 
$c=substr($in,$pos,1); 
$out.=$c; 
} 
else 
{ 
$out.=$c; 
} 
$pos++; 
if($pos>=$num) break; 
} 
return $out; 
} //by www.jbxue.com
echo SubstrGB($string,8) ; 
?> 

2，截取中文字符

<?php 
/** 
* cut_string.php 
* ------------------------------ 
* 截取中文字符. 
* edit by www.jbxue.com 
*/ 
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 $tmpstr; 
} 
} 
echo "<br>".cut_str($string,8,$start=0,$code='sdf') ; 
?>