mysqli results not filling in values - php

Question

I've been trying to create an array from a mysqli query that creates a new class 'Book'. When I run this code, it returns the correct number of rows that I have in my database, but it won't display any of the values in the rows. Definitely a newb to a lot of this stuff, any help is really appreciated! Here's the code I'm running. If I just put in a pre-populated array, the code all works great. My problem is getting the values from the database into this array.
$db = new db();
$conn = $db->connect();
$sql = "SELECT * FROM users";
$result = mysqli_query($conn, $sql);
$thearray = array();
while($array_ar = mysqli_fetch_array($result)){
$thearray[] = array(
$array_ar['username'] => new Book($array_ar['username'], $array_ar['first_name'], $array_ar['last_name']),
);
}
echo 'Rows found: ' . mysqli_num_rows($result);
return $thearray;
Ok, so I var_dump($thearray); and it gives me a multidimensional array, which is why it's returning empty values. I think I need it to return an associative array? Here's what it var_dump($thearray); returns:
array(4) {
[0]=> array(1) {
["joshua"]=> object(Book)#6 (3) {
["title"]=> string(6) "joshua" ["author"]=> string(6) "Joshua" ["description"]=> string(9) "Lundquist"
}
}
[1]=> array(1) {
["matthew"]=> object(Book)#7 (3) {
["title"]=> string(7) "matthew" ["author"]=> string(4) "Matt" ["description"]=> string(3) "Alm"
}
}
[2]=> array(1) {
["roger"]=> object(Book)#8 (3) {
["title"]=> string(5) "roger" ["author"]=> string(5) "Roger" ["description"]=> string(9) "Lundquist"
}
}
[3]=> array(1) {
["norm"]=> object(Book)#9 (3) {
["title"]=> string(4) "norm" ["author"]=> string(4) "Norm" ["description"]=> string(5) "Shupe"
}
}
}
Next I thought I would take a look at what the var_dump(); for my hard-coded array looks like, and it output this (this one works):
array(3) {
["Jungle Book"]=> object(Book)#3 (3) {
["title"]=> string(11) "Jungle Book" ["author"]=> string(10) "R. Kipling" ["description"]=> string(15) "A classic book."
}
["Moonwalker"]=> object(Book)#4 (3) {
["title"]=> string(10) "Moonwalker" ["author"]=> string(9) "J. Walker" ["description"]=> string(7) "another"
}
["PHP for Dummies"]=> object(Book)#5 (3) {
["title"]=> string(15) "PHP for Dummies" ["author"]=> string(14) "Some Smart Guy" ["description"]=> string(18) "and the final one."
}
}
It makes sense to me what's happening, but I'm not sure how to fix my code. Thank you for the help!

Answer 1

Don't Panic's answer got me looking in the right direction. I needed to create an associative array, not a multidimensional array. At first I was accidentally creating the multidimensional array by setting $thearray equal to "array();". By removing that, it filled in the values correctly. Thanks again for the help!
$db = new db();
$conn = $db->connect();
$sql = "SELECT * FROM users";
$result = mysqli_query($conn, $sql);
$thearray = array();
while($array_ar = mysqli_fetch_array($result)){
$title = $array_ar['username'];
$author = $array_ar['username'];
$description = $array_ar['username'];
$thearray[] = $title = new Book($title, $author, $description);
}
var_dump($thearray);
echo 'Rows found: ' . mysqli_num_rows($result);
return $thearray;

Answer 2

I think this is the problem.
$thearray[] = array(
$array_ar['username'] => new Book(
$array_ar['username'], $array_ar['first_name'], $array_ar['last_name']),
);
It looks like the differences between what you're getting and what you want is 1) You're wrapping the input to $thearray in an extra array() layer, and 2) You won't get string keys like you have in your hard-coded array if you just add the items using [].
Try it like this instead:
// use the username as a key, since that is what it looks like you're using as the 'title'
$thearray[$array_ar['username']] = new Book(
$array_ar['username'], $array_ar['first_name'], $array_ar['last_name']);