PHP比较2个数组数组

Question

Hi All I have 2 arrays for example in PHP as seen below:

[users] => Array ( [0] => Array ( [username] => Timothy ) [1] => Array ( [username] => Frederic ) ) 

[users2] => Array ( [0] => Array ( [username] => Johnathon ) [1] => Array ( [username] => Frederic ) [] => Array ( [username] => Peter))

I am trying to compare the contents of each array against each other in order to put a html element, I tried using a nested foreach as seen below:

foreach($users as $user){
    foreach ($users2 as $user2){
        if($user['username'] == $user2['username']){
            echo "<option value=' ".$user['username']."' selected = 'selected'>".$user['username']."</option>";
            break;
        } else{
            echo "<option value=' ".$user['username']."'>".$user['username']."</option>";
        }
    }
}

my issue is that the items are being echoed more than once which is ruining my select element. Any ideas on how to compare the contents of each?

I want to achieve a list of each name eg:

-Timothy
-Frederic (this should be highlighted as it is in both arrays)
-Johnathon
- Peter

Answer 1

I would take it in a different way.

//Create user array one
$users = array();
$users[] = array('username'=>'Timothy');
$users[] = array('username'=>'Frederic');

//create user array 2
$users2 = array();
$users2[] = array('username'=>'Johnathon');
$users2[] = array('username'=>'Frederic');
$users2[] = array('username'=>'Peter');

$temp_array = array();

foreach($users as $key => $value) {
    $temp_array[$value['username']] = '';
}

foreach($users2 as $key => $value) {
    $temp_array[$value['username']] = array_key_exists($value['username'], $temp_array) ? 'DUPLICATE' : null;
}

echo '<select>';
foreach($temp_array as $key_value => $status) {
    echo "<option value='{$key_value}' ".(($status == 'DUPLICATE') ? 'selected style="background-color: yellow;"' : '').">{$key_value}</option>";
}
echo '</select>';

I'll let the array take care of it self, if it shares the same key, it will merge, then just flag it with "duplicate".