php 截取中文字符串方法
/** * 截取中文字符串函数 * @param $str 需要截取的字串 * @param $start 开始截取的位置 * @param $length 截取的长度 * @return 此函数返回的是一个数组,因此要配合join函数来显示字符串:join('',subString_UTF8($str, $start, $lenth)); */ public function subString_UTF8($str, $start, $lenth){ $len = strlen($str); $r = array(); $n = 0; $m = 0; for($i = 0; $i < $len; $i++) { $x = substr($str, $i, 1); $a = base_convert(ord($x), 10, 2); $a = substr('00000000'.$a, -8); if ($n < $start){ if (substr($a, 0, 1) == 0) { }elseif (substr($a, 0, 3) == 110) { $i += 1; }elseif (substr($a, 0, 4) == 1110) { $i += 2; } $n++; }else{ if (substr($a, 0, 1) == 0) { $r[ ] = substr($str, $i, 1); }elseif (substr($a, 0, 3) == 110) { $r[ ] = substr($str, $i, 2); $i += 1; }elseif (substr($a, 0, 4) == 1110) { $r[ ] = substr($str, $i, 3); $i += 2; }else{ $r[ ] = ''; } if (++$m >= $lenth){ break; } } } return $r; } // End subString_UTF8;