unset array key not working

Question

I am trying to get an associative aray from a form input, which works ok. But i dont want the new value to duplicate if the key already exist in the array. Here is how my $_POST function looks:

<?php // top of page
if ( isset( $_POST['drw_inventory'] ) && wp_verify_nonce($_POST['drw_inventory'],'update_drw_postmeta') )
{
      //if nonce check succeeds.
      global $post;
      $postid = $post->ID;
      $data = $_POST['wpd_function_rating'];
      $currentusr = wp_get_current_user();

      //Get the Existing user ratings of this post
      $ls_up_votes = (get_post_meta($postid, 'wpd_rating', TRUE ));

      //if the current user already rated, unset the rating
      foreach($ls_up_votes as $arr) {
          foreach($arr as $key => $value) {
              if (array_key_exists($currentusr->user_login, $arr)) {
                    unset($arr[$key]);
               }
          }
      }   
      //Add post meta 'wpd_rating' with this structure: 
      $ls_up_votes[] = array($currentusr->user_login => $data);
      update_post_meta($postid,'wpd_rating',$ls_up_votes);  
}
?>

The Form

<form method="post" action="">
   <?php wp_nonce_field('update_drw_postmeta','drw_inventory'); ?>
   <label>This is label</label>
   <input type='text' name='wpd_function_rating' value='' />
   <input type='submit' value='save' />
</form>

This is how my array looks(you can see the duplicate user inputs, I want the array value to be updated on the existing username key):

Array ( 
[0] => Array ( [user1] => 33 ) 
[1] => Array ( [user1] => 44 ) 
[2] => Array ( [user2] => 34 ) 
[2] => Array ( [user2] => 31 ) 
) 

Any help would be appreciated.

Answer 1

foreach ( $ls_up_votes as $k => $v ) {
    foreach ( $v as $k2 => $v2 ) {
        if ( array_key_exists($currentusr->user_login, $v) ) {
            unset($ls_up_votes[$k][$k2]);
        }
    }
}