/**

 * 隐藏部分字符串

 * # 此方法多用于手机号码或身份证号、银行卡号的中间部分数字的隐藏

 */

function func_substr_replace($str, $replacement = '*', $start = 1, $length = 3)

{

    $len = mb_strlen($str,'utf-8');

    if ($len > intval($start+$length)) {

        $str1 = mb_substr($str,0,$start,'utf-8');

        $str2 = mb_substr($str,intval($start+$length),NULL,'utf-8');

    } else {

        $str1 = mb_substr($str,0,1,'utf-8');

        $str2 = mb_substr($str,$len-1,1,'utf-8');

        $length = $len - 2;

    }

    $new_str = $str1;

    for ($i = 0; $i < $length; $i++) {

        $new_str .= $replacement;

    }

    $new_str .= $str2;

    return $new_str;

}

/**

 * 只保留字符串首尾字符，隐藏中间用*代替（两个字符时只显示第一个）

 * @param string $user_name 姓名

 * @return string 格式化后的姓名

 */

function substr_cut($user_name){

    $strlen   = mb_strlen($user_name, 'utf-8');

    $firstStr   = ucfirst(strtolower(mb_substr($user_name, 0, 3, 'utf-8')));

    $lastStr   = strtolower(substr($user_name, -3));

    if($strlen == 2){

        $hideStr = str_repeat('*', strlen($user_name, 'utf-8') - 1);

        $result = $firstStr . $hideStr ;

    }else {

        $hideStr = substr(str_repeat("*", $strlen - 6), 0, 3);

        $result = $firstStr . $hideStr . $lastStr;

    }

    return $result;

}