How to fix "Array index out of range?" - php

Question

When logging into my Unity project, I get error "Array index is out of range" at this line of my C# code
if (www.text[0] == '0')
www.text pulls from this php script (www.text is returning null when debugging so it must be an error with my script).
<?php
$con = mysqli_connect('localhost', 'root', 'root', 'unityaccess');
//check that connection happened
if (mysqli_connect_errno())
{
echo "1: Connection failed"; //error code #1 = connection failed
exit();
}
$username = $_POST["name"];
$password = $_POST["password"];
//check if name exists
$namecheckquery = "SELECT username, salt, hash, score FROM players WHERE
username = ' " . $username . "';";
$namecheck = mysqli_query($con, $namecheckquery) or die("2: Name check query
failed"); //error code #2 - name check query failed
if (mysqli_num_rows($namecheck) != 1)
{
echo "5: Either no user with name, or more than one";
exit();
}
//get login info from query
$existinginfo = mysqli_fetch_assoc($namecheck)
$salt= $existinginfo["salt"];
$hash = $existinginfo["hash"];
$loginhash = crypt($password, $salt);
if($hash != $loginhash)
{
echo "6: Incorrect password"; //error code #6 - password does not hash to
match table
exit();
}
echo "0\t" . $existinginfo["score"];
?>
I'm following a tutorial and am new to php and sql.
https://www.youtube.com/watch?v=NVdjlXgbiMM
In the tutorial his code is exactly the same as mine. Looking at it myself I would assume that the echo "0\t" . $existinginfo["score"]; is the problem, and that putting a tab isn't separating it into an array. In his code he runs it and it's fine though, so I must be missing something else?

Answer 1

You have a space after the ' in the query on this line:
$namecheckquery = "SELECT username, salt, hash, score FROM players WHERE
username = ' " . $username . "';";
So if the username entered is user1 it will look in the database for <space>user1 (where <space> means a space character). Remove that space.
$namecheckquery = "SELECT username, salt, hash, score FROM players WHERE
username = '" . $username . "';";
Actually, it would be even better if you learned to use prepared statements, then problems like this are nearly impossible, as well as making the code safe from SQL-injection. Read How can I prevent SQL injection in PHP?