Issues getting PHP shuffle to output results - php

Question

I'm attempting to shuffle the users that I have in my database and then output the first and last name of those results. I have PHP error coding in this file and it is not throwing any errors. Just nothing is outputting not even..
if ($shuffle_firstname == true) {
echo $shuffle_firstname . $shuffle_lastname;
} else {
echo "No users have been registered yet.";
}
Does anyone see what I'm doing wrong?
$con = mysqli_connect("localhost", "root", "", "db");
$shuffle_run = mysqli_query($con,"SELECT * FROM users WHERE `group`= 3");
$shuffle_numrows = mysqli_num_rows($shuffle_run);
if( $shuffle_numrows > 0) {
while($shuffle_row = mysqli_fetch_assoc($shuffle_run)){
$shuffle_id = $shuffle_row['id'];
$shuffle_firstname = $suffle_row['firstname'];
$shuffle_lastname = $shuffle_row['lastname'];
$shuffle_username = $shuffle_row['username'];
$shuffle_email = $shuffle_row['email'];
if ($shuffle_firstname == true) {
echo $shuffle_firstname . $shuffle_lastname;
} else {
echo "No users have been registered yet.";
}
}
}
if(isset($_POST['shuffle'])) {
$shuffle_row = array();
shuffle($shuffle_row);
foreach ($shuffle_row as $shuffle) {
echo $shuffle_firstname . " " . $shuffle_lastname;
}
}
?>
<input type="submit" value="Shuffle" name="shuffle">

Answer 1

You are overwriting your results with an empty array, then you use shuffle on an empty array, then you're looping the empty array using foreach. I've cleaned up the code, could you try this?
<?php
$con = mysqli_connect("localhost", "root", "", "db");
$query = mysqli_query($con, "SELECT * FROM users WHERE `group` = 3");
echo 'Normal results: <br>';
$array = array();
while ($row = mysqli_fetch_assoc($query)) {
$array[] = $row;
echo $row['firstname'] . ' ' . $row['lastname'] . '<br>';
}
if (isset($_POST['shuffle'])) {
shuffle($array);
echo 'Shuffled results: <br>';
foreach ($array as $result) {
echo $result['firstname'] . ' ' . $result['lastname'] . '<br>';
}
// echo $results[0]['firstname'] . ' ' . $results[0]['lastname']; // To display one random result
}
?>
<form method="post">
<input type="submit" value="Shuffle" name="shuffle">
</form>