Есть такой код :

$html = str_get_html($content);         
                
                $div = $html->find('table tbody',0);
                    $i = 0;
                    while($article = $div->children($i++)){
                        
                        $item['marka'] = $article->find('td.title',0)->plaintext;
                        $item['cena']  = $article->find('td[width=423]',0)->plaintext;
                        $item['data']  = $article->find('td[width=45]',0)->plaintext;
                        $item['autor']  = $article->find('td[width=186]',0)->plaintext;
                        
                        
                             $articles[] = $item;
                    }

на выходе поучаю такой массив :

print_r($articles);
 
Array
(
    [marka] => audi
    [cena] => 
    [data] => 12.06.2006
    [autor] => 
)
Array
(
    [marka] => 
    [cena] => 
    [data] => 
    [autor] => Max
)
Array
(
    [marka] => bmw
    [cena] => 32.000
    [data] => 
    [autor] => 
)
Array
(
    [marka] => 
    [cena] => 
    [data] => 
    [autor] =>Sanya
)
Array
(
    [marka] => lexus
    [cena] => 
    [data] => 3.04.2004
    [autor] =>Andrey
)
Array
(
    [marka] => 
    [cena] => 
    [data] => 
    [autor] =>
)
Array
(
    [marka] => honda
    [cena] => 
    [data] => 
    [autor] => Vasya
)
Array
(
    [marka] => 
    [cena] => 
    [data] => 
    [autor] =>
)
Array
(
    [marka] => audi
    [cena] => 20.000
    [data] => 
    [autor] =>
)
Array
(
    [marka] => 
    [cena] => 
    [data] => 
    [autor] => 
)

как убрать пустые значения и объединить массивы.

Array
(
    [marka] => audi
    [data] => 12.06.2006
    [autor] => Max
Array
(
    [marka] => bmw
    [cena] => 32.000
    [autor] =>Sanya
)
Array
(
    [marka] => lexus
    [data] => 3.04.2004
    [autor] =>Andrey
)
Array
(
    [marka] => honda
    [autor] => Vasya
)
Array
(
    [marka] => audi  
    [cena] => 20.000
)