Function code for calculating the length of Chinese strings and intercepting Chinese strings in PHP_PHP Tutorial

header('Content-type: text/html;charset=utf-8') ;
/**
* Function that can count the length of Chinese strings
* @param $str String to calculate the length
* @param $type Calculation length type, 0 (default) means one Chinese character is counted as one character, 1 Indicates that one Chinese character counts as two characters
*
*/
function abslength($str)
{
if(empty($str)){
return 0;
}
if(function_exists('mb_strlen')){
return mb_strlen($str,'utf-8');
}
else {
preg_match_all("/./u", $str, $ar);
return count($ar[0]);
}
}
$str = 'We are all Chinese, ye! ';
$len = abslength($str);
var_dump($len); //return 12
$len = abslength($str,'1');
echo '< br />'.$len; //return 22
/*
Intercept the Chinese string under utf-8 encoding. The parameters can refer to the substr function
@param $str The string to be intercepted
@param $start The starting position to intercept, negative number means reverse interception
@param $end The length to intercept
*/
function utf8_substr($str,$start=0) {
if(empty($str)){
return false;
}
if (function_exists('mb_substr')){
if(func_num_args() >= 3) {
$end = func_get_arg(2);
return mb_substr($str,$start,$end,'utf-8');
}
else {
mb_internal_encoding("UTF-8 ");
return mb_substr($str,$start);
}
}
else {
$null = "";
preg_match_all("/./u", $str, $ar);
if(func_num_args() >= 3) {
$end = func_get_arg(2);
return join($null, array_slice($ar[0],$ start,$end));
}
else {
return join($null, array_slice($ar[0],$start));
}
}
}
$str2 = 'wo wants to intercept zhongwen';
echo '
';
echo utf8_substr($str2,0,-4); //return wo wants to intercept zhon

/*
* Chinese interception, supports gb2312, gbk, utf-8, big5
*
* @param string $str String to intercept
* @param int $start Interception starts Starting position
* @param int $length interception length
* @param string $charset utf-8|gb2312|gbk|big5 encoding
* @param $suffix whether to add a suffix
*/
public function csubstr($str, $start=0, $length, $charset="utf-8", $suffix=true)
{
if(function_exists("mb_substr"))
{
if(mb_strlen($str, $charset) <= $length) return $str;
$slice = mb_substr($str, $start, $length, $charset);
}
else
{
$re['utf-8'] = "/[x01-x7f]|[xc2-xdf][x80-xbf]|[xe0-xef][x80-xbf]{ 2}|[xf0-xff][x80-xbf]{3}/";
$re['gb2312'] = "/[x01-x7f]|[xb0-xf7][xa0-xfe]/" ;
$re['gbk'] = "/[x01-x7f]|[x81-xfe][x40-xfe]/";
$re['big5'] = "/[x01-x7f ]|[x81-xfe]([x40-x7e]|xa1-xfe])/";
preg_match_all($re[$charset], $str, $match);
if(count($match [0]) <= $length) return $str;
$slice = join("",array_slice($match[0], $start, $length));
}
if( $suffix) return $slice."…";
return $slice;
}