Parse error: syntax error, unexpected '?' - php

Question

I have been trying to follow a guide for making a PHP server app and I am getting a few syntax errors.
Error message:
Parse error: syntax error, unexpected '?' in
D:\inetpub\wwwroot\cmpswoo1\CMPPROJ_Web\ServerApp\api2\db_functions2.php on line 134
So I know were the error is, I just don't know how to fix it
<?php
class db_functions2 {
private $db;
//put your code here
// constructor
function __construct() {
require_once 'db_connect2.php';
// connecting to database
$this->db = new db_connect2();
$this->db->connect();
}
// destructor
function __destruct() {
}
/**
* Random string which is sent by mail to reset password
*/
public function random_string()
{
$character_set_array = array();
$character_set_array[] = array('count' => 7, 'characters' => 'abcdefghijklmnopqrstuvwxyz');
$character_set_array[] = array('count' => 1, 'characters' => '0123456789');
$temp_array = array();
foreach ($character_set_array as $character_set) {
for ($i = 0; $i < $character_set['count']; $i++) {
$temp_array[] = $character_set['characters'][rand(0, strlen($character_set['characters']) - 1)];
}
}
shuffle($temp_array);
return implode('', $temp_array);
}
public function forgotPassword($forgotpassword, $newpassword, $salt){
$result = mysql_query("UPDATE `Users` SET `encryptedPassword` = '$newpassword',`salt` = '$salt'
WHERE `email` = '$forgotpassword'");
if ($result) {
return true;
}
else
{
return false;
}
}
/**
* Adding new user to mysql database
* returns user details
*/
public function storeUser($FirstName, $LastName, $DOB, $email, $Username, $Password) {
$uuid = uniqid('', true);
$hash = $this->hashSSHA($Password);
$encrypted_password = $hash["encrypted"]; // encrypted password
$salt = $hash["salt"]; // salt
$result = mysql_query("INSERT INTO Users(unique_id, FirstName, LastName, email, DOB, Username, encryptedPassword, salt, created_at) VALUES('$uuid', '$FirstName', '$LastName', '$email', '$DOB', '$Username', '$encryptedPassword', '$salt', NOW())");
// check for successful store
if ($result) {
// get user details
$uid = mysql_insert_id(); // last inserted id
$result = mysql_query("SELECT * FROM Users WHERE uid = $id");
// return user details
return mysql_fetch_array($result);
} else {
return false;
}
}
/**
* Verifies user by username and password
*/
public function getUserByUsernameAndPassword($Username, $Password) {
$result = mysql_query("SELECT * FROM Users WHERE usernameE = '$Username'") or die(mysql_error());
// check for result
$no_of_rows = mysql_num_rows($result);
if ($no_of_rows > 0) {
$result = mysql_fetch_array($result);
$salt = $result['salt'];
$encrypted_password = $result['encryptedPassword'];
$hash = $this->checkhashSSHA($salt, $Password);
// check for password equality
if ($encryptedPassword == $hash) {
// user authentication details are correct
return $result;
}
} else {
// user not found
return false;
}
}
/**
* Checks whether the username is valid or fake
*/
public function validUsername($Username)
{
$isValid = true;
$atIndex = strrpos($Username, "#");
if (is_bool($atIndex) && !$atIndex)
{
$isValid = false;
}
else
{
$domain = substr($Username, $atIndex+1);
$local = substr($Username, 0, $atIndex);
$localLen = strlen($local);
$domainLen = strlen($domain);
if ($localLen < 1 || $localLen > 64)
{
// local part length exceeded
$isValid = false;
}
else if ($domainLen < 1 || $domainLen > 255)
{
// domain part length exceeded
$isValid = false;
}
else if ($local[0] == '.' || $local[$localLen-1] == '.')
{
// local part starts or ends with '.'
$isValid = false;
}
else if (preg_match('/\.\./', $local))
{
// local part has two consecutive dots
$isValid = false;
}
else if (!preg_match('/^[A-Za-z0-9\-\.]+$/', $domain))
{
// character not valid in domain part
$isValid = false;
}
else if (preg_match('/\.\./', $domain))
{
// domain part has two consecutive dots
$isValid = false;
}
else if
(!preg_match('/^(\\.|[A-Za-z0-9!#%&`_=\/$'*+?^{}|~.-])+$/',str_replace("\\","",$local)))
{
// character not valid in local part unless
// local part is quoted
if (!preg_match('/^"(\\"|[^"])+"$/',
str_replace("\\","",$local)))
{
$isValid = false;
}
}
if ($isValid && !(checkdnsrr($domain,"MX") ||checkdnsrr($domain,"A")))
{
// domain not found in DNS
$isValid = false;
}
}
return $isValid;
}
/**
* Check user is existed or not
*/
public function isUserExisted($Username) {
$result = mysql_query("SELECT Username from Users WHERE Username = '$Username'");
$no_of_rows = mysql_num_rows($result);
if ($no_of_rows > 0) {
// user existed
return true;
} else {
// user not existed
return false;
}
}
/**
* Encrypting password
* returns salt and encrypted password
*/
public function hashSSHA($Password) {
$salt = sha1(rand());
$salt = substr($salt, 0, 10);
$encrypted = base64_encode(sha1($Password . $salt, true) . $salt);
$hash = array("salt" => $salt, "encrypted" => $encrypted);
return $hash;
}
/**
* Decrypting password
* returns hash string
*/
public function checkhashSSHA($salt, $Password) {
$hash = base64_encode(sha1($Password . $salt, true) . $salt);
return $hash;
}
}
?>

Answer 1

Here single quote is causing problem:
So, change
(!preg_match('/^(\\.|[A-Za-z0-9!#%&`_=\/$'*+?^{}|~.-])+$/',str_replace("\\","",$local)))
To:
(!preg_match('/^(\\.|[A-Za-z0-9!#%&`_=\/$\'*+?^{}|~.-])+$/',str_replace("\\","",$local)))

Answer 2

The regular expression string is opened with ', but also contains a '. Escape it with \. The error should be gone.
(!preg_match('/^(\\.|[A-Za-z0-9!#%&`_=\/$'*+?^{}|~.-])+$/',str_replace("\\","",$local)))
Should be
(!preg_match('/^(\\.|[A-Za-z0-9!#%&`_=\/$\'*+?^{}|~.-])+$/',str_replace("\\","",$local)))