试图比较两个数组中的值

Question

I have a list of users on a webpage and am trying to compare each username with a list of users in an array. But for some reason the following code always returns false. Some usernames do match and should therefore display a yes next to the username.

foreach($result AS $user){
    foreach($listarray AS $name){
        if($user['username'] == $name){
            $whitelisted = 'Yes';
        } else {
            $whitelisted = 'No';
        }
    }
    echo '<tr><td><p>'.$user['username'].'</p></td><td><p>'.$user['location'].'</p></td><td><p>'.$user['date_joined'].'</p></td><td><p>'.$whitelisted.'</p></td>';
}

Why is this comparison returning false even when some names should match?

Answer 1

You need to break the inner foreach loop if there is a matching element. Alternatively you can use the in_array function to check if there is value exists in an array

foreach($result AS $user){
    $whitelisted = 'No';
    if (in_array($user['username'], $listarray ))
    {
       $whitelisted = 'Yes';
    }
    echo '<tr><td><p>'.$user['username'].'</p></td><td><p>'.$user['location'].'</p></td><td><p>'.$user['date_joined'].'</p></td><td><p>'.$whitelisted.'</p></td>';
}