Александр N++

<input type="text" name="quantity[<?php echo $product['key']; ?>]" value="<?php echo $product['quantity']; ?>"  size="1" class="form-cart" style="display:none;">
<select class="countOrders" value="<?php echo $product['quantity']; ?>" >
  <?php for($i=1; $i<=20; $i++):?>
			<option value="<?=$i?>" <?=($i == $product['quantity'] ? ' selected="selected"' : '' )?>><?=$i?> шт</option>
	   <?php endfor;?>
</select>
<span class="input-group-btn">
	<button type="button" data-toggle="tooltip" class="btn btn-danger"  onclick="cart.remove('<?php echo $product['key']; ?>');"><i class="fa fa-times-circle"></i></button>
</span>

Гдето внизу подключить
<script>
$( document ).ready(function() {
	$('.countOrders').on('change', function(e){
		$(this).prev().val( $(this).val() );
		$('#cart-form2').submit();
	})
});
</script>

<input type="text" name="quantity[<?php echo $product['key']; ?>]" value="<?php echo $product['quantity']; ?>"  size="1" class="form-cart" style="display:none;"/>
<select class="countOrders" value="<?php echo $product['quantity']; ?>"  onchange="$(this).prev().val( $(this).val()); $('#cart-form2').submit(); " >

  <?php for($i=1; $i<=20; $i++):?>
			<option value="<?=$i?>" <?=($i == $product['quantity'] ? ' selected="selected"' : '' )?>><?=$i?> шт</option>
	   <?php endfor;?>
</select>
<span class="input-group-btn">
	<button type="button" data-toggle="tooltip" class="btn btn-danger"  onclick="cart.remove('<?php echo $product['key']; ?>');"><i class="fa fa-times-circle"></i></button>
</span>
<code>

<?php $arrAttr = ['icq' => 'Label ICQ' , 'email' => 'Ваш email' ]; ?>
<?php foreach($arrAttr as $key=> $attr):?>
     <?php if (property_exists($user, $key)) :  ?>
           <p class='attr'><?= $attr?></p><p><?=$user->{$key}; ?></p>
      <?php endif; ?>
<?php endforeach;?>

class DB {
   public static $pdo = null;
   public static function connect(){
        if(self::$pdo === null ){
               self::$pdo = connectDB($host,$user,$pass,$db,$charset);
         }
       return self::$pdo;
  }
}

<?php 
return [
              'host => 'localhost',   'username' => 'root' , 'password' => 122
];