Remove duplicate names in a text file with php

Question

i am faily new to php, and don't really know what i am doing, but understand the logic.

I have this script witch lists users in userclass 1 and 8, so when a user is in userclass 8, he is also in userclass 1. And userclass 1 is just 1. What i need is to strip the duplicate username when the user is in class 8.

Any help is much appreciated! Been trying for several hours on my own now lol!

<?php

    require_once("../../class2.php");

    function list_users($uclass = 1){

    $u_sql = new db();
    $result = array();

    $query = "SELECT user_id, user_class, user_name FROM #user WHERE find_in_set('{$uclass}', user_class) ORDER BY user_id";

    if ($u_sql->db_Select_gen($query, true)){

        while ($row = $u_sql->db_Fetch(MYSQL_ASSOC)){
           $result[] = $row['user_name'];
        }

    }
    if (count($result))
    {
        return implode("\n", $result);
    }
    else
    {
        return ("Ingen i klasse ". $uclass);
    }
}
$text = list_users(1)."\n".list_users(8);

$file = "reserved_slots.txt";
    $handle = fopen($file, 'w') or die("can't open file");
    $data = $text;
    fwrite($handle, $data); 
    fclose($handle); 

$ns->tablerender($text);`enter code here`

Answer 1

Use PHP's array_unique function http://php.net/manual/en/function.array-unique.php

$text = list_users(1)."\n".list_users(8);

$names = explode("\n", $text);
$names = array_unique($names);
$text = implode("\n", $names);

$file = "reserved_slots.txt";