foreach ($array as $arr) 
{
    echo "<div>".implode(' ',$arr)."</div>";
}

$files = [
  '1.file',
  '2.file',
];
$resultFile = 'result.file';
$res = fopen($resultFile,'a+');
foreach ($files as $file) {
  $f = fopen($file,'r');
  while (!feof($f)) {
    $contents = fread($f,8192);
    fputs($res,$contents);
  }
}

$datetime1 = new DateTime();
$datetime2 = new DateTime('2009-10-13');
$interval = $datetime1->diff($datetime2);
echo $interval->format('%R%a дней');