当变量的顺序不同时，PHP函数无法与数组一起正常运行

Question

I have a PHP function. The function checks names and, if they do not exist, dies. It strips out spaces from the names, and adds the name of the current user logged in if they are not already in the list.

function create_group($name, $description, $invites){
    global $link;
    $invitesarr = explode(',', $invites);
    $user_id = $_SESSION['user_id']; //avoids issues with quotations (either invalid quotation for referring to PHP variable or repeated double quotes)
    $result = mysqli_query($link, "SELECT `username` FROM `users` WHERE `user_id` = '$user_id'");
    foreach($result as $resul){
        foreach($resul as $resu){
            $logged_in_username = $resu;
        }}
    if(in_array($logged_in_username, $invitesarr)){
    }else{
        $invitesarr[] = $logged_in_username;
    }

    foreach($invitesarr as $invite) {
        $idres = mysqli_query($link, "SELECT `user_id` FROM `users` WHERE `username` = '$invite'");
        $invite = preg_replace('/\s+/', '', $invite);
        print $invite;
        if(mysqli_num_rows($idres) == 0) {
            exit("1 or more of the users that you entered do(es) not exist!");
        }
    }

    $name = mysqli_real_escape_string($link, $name);
    $description = mysqli_real_escape_string($link, $description);
    $names = mysqli_query($link, "SELECT `group_name` FROM `groups` WHERE `group_name` = '$name'");
    $descriptions = mysqli_query($link, "SELECT `group_description` FROM `groups` WHERE `group_description` = '$description'");
    if(mysqli_num_rows($names) == 0 && mysqli_num_rows($descriptions) == 0) {
        mysqli_query($link, "INSERT INTO `groups` (`group_name`, `group_description`) VALUES ('$name', '$description')");
    } else {
        echo 'Group with that name/description already exists.';
    }

    $result = mysqli_query($link, "SELECT `group_id` FROM `groups` WHERE `group_name` = '$name'");

    foreach($result as $resul) {
        foreach($resul as $resu) {
            $group_id = $resu;
        }
    }
    foreach($invitesarr as $invite) {
        $idres = mysqli_query($link, "SELECT `user_id` FROM `users` WHERE `username` = '$invite'");
        foreach($idres as $idarr) {
            foreach($idarr as $id) {
                mysqli_query($link, "INSERT INTO `group_members` (`group_id`, `user_id`, `confirmed?`) VALUES ('$group_id', '$id', 0)");
            }
        }
    }
}

It works perfectly, except for when a user enters their name and it goes into the $invitesarr array. When I put a print statement in the foreach statement that checks names, I notice that, when the user's name is not entered into the field (which posts) the names are in the order name1 loggedinname, whereas when I enter the user's name it becomes loggedinname name1. This seems to be significant.

Answer 1

You need to put:

$invite = preg_replace('/\s+/', '', $invite);

before the line:

$idres = mysqli_query($link, "SELECT `user_id` FROM `users` WHERE `username` = '$invite'");