php return an empty array after foeach
===

Can I avoid the empty array that generate by `foreach` ?<br>
here is my code

    $file="test.txt";
    $open = file_get_contents($file);
    $lines = explode(PHP_EOL, $open);
    foreach($lines as $line){
    $domain = preg_split('/\s+/', $line,-1,PREG_SPLIT_NO_EMPTY);
    echo "<pre>";
    var_dump($domain);
    echo "$domain[0] OK";
    echo "</pre>";
    }

test.txt contains this

    www.google.com  2.2.2.3
    www.test.com    2.2.2.3
    www.example.com 2.2.2.3

after I ran my script the result is this

    array(2) {
      [0]=>
      string(14) "www.google.com"
      [1]=>
      string(7) "2.2.2.3"
    }
    www.google.com OK
    array(2) {
      [0]=>
      string(12) "www.test.com"
      [1]=>
      string(7) "2.2.2.3"
    }
    www.test.com OK
    array(2) {
      [0]=>
      string(15) "www.example.com"
      [1]=>
      string(7) "2.2.2.3"
    }
    www.example.com OK
    array(0) {
    }
     OK

What cause the `array(0)` to appear?<br>
There's no new line after www.example.com or other element.<br>
Can I remove it or simply don't get it generated?