PHP实现的只保留字符串首尾字符功能示例【隐藏部分字符串】

/*** 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');  $firstStr   = mb_substr($user_name, 0, 1, 'utf-8');  $lastStr   = mb_substr($user_name, -1, 1, 'utf-8');  return $strlen == 2 ? $firstStr . str_repeat('*', mb_strlen($user_name, 'utf-8') - 1) : $firstStr . str_repeat("*", $strlen - 2) . $lastStr;}