Question

PHP截取字符串长度

比方说我现在有一个变量A，A是字符串，有200个汉字，我想只输出前100个汉字，请问如何实现。

Answer 1

php截取中文字符串无乱码函数:

function ZHsubstr($str, $start=0, $length, $charset="utf-8"){
$len = strlen($str); //原字节数
if($len > $length)
$suffixStr = "…";
else
$suffixStr = "";

if(function_exists("mb_substr"))
return mb_substr($str, $start, $length, $charset).$suffixStr;
elseif(function_exists('iconv_substr')) {
return iconv_substr($str,$start,$length,$charset).$suffixStr;
}
$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);
$slice = join("",array_slice($match[0], $start, $length));
return $slice.$suffixStr;
}

使用方法：

$str = "$page_title";
$page_title=ZHsubstr($str, 0, 40, 'utf-8');

Answer 2

$str = '任意长度字符串';
echo mb_substr($str,0,100,'字符集')；

追问

echo mb_substr($str,0,100,'字符集')；

中的 字符集是什么意思？

追答

“UTF-8”或“GBK”，看你文件的编码格式。