function replaceStar($str, $start = 0, $end = 0, $dot = '*') {if(empty($str)) return '';mb_internal_encoding('UTF-8');$length = mb_strlen($str);/*** 1、当昵称为2个字时：例如：测试 展示为：测*，数字字母也一样* 2、当昵称为3个字时：例如：测试中，展示位：测*中，数字字母也一样* 3、当昵称大于3个字时：和现在平台的保持一致* @time 2017-06-13*/if($length == 2){$start = $length -1;$end = 0;}else if($length == 3 || $length == 4){$start = $length - 2;$end = -1;}if(abs($start) > $length){$start = 2;}if(abs($end) > $length){$end = -2;}$preStr = mb_substr($str, 0, $start);$extStr = '';if($end !== 0){$extStr = mb_substr($str, $end);}return $preStr . str_repeat($dot, ($length - $start + $end) % $length) . $extStr;
}