Complete collection of PHP string interception methods Four examples of PHP string interception-PHP Tutorial-php.cn

Complete collection of PHP string interception methods Four examples of PHP string interception

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Release： 2016-07-25 08:51:33

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2. Intercept utf8 encoded multi-byte string

//Intercept utf8 string
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);
} ?>

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3, UTF-8, and GB2312 support Chinese character interception function

/*
The Chinese character interception function cut_str (string, interception length, starting length, encoding) supported by Utf-8 and gb2312; the default encoding is utf-8 and the default starting length is 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; } } $str = "abcd string to be intercepted"; echo cut_str($str, 8, 0, 'gb2312'); ?>