Loop row in bootstrap every 3 columns

Question

I want every row in my page to display 3 thumbnails, but its stacked in one row.

How do I manage the looping? Thank you...

<?php
    foreach ($rows as $row){
?>  
        <div class="col-md-3">
            <div class="thumbnail">
                <img src="user_file/<?php echo $row->foto; ?>">
            </div>
        </div>

<?php
}
?>

This code generates stacked thumbnails in a row. How can I generate the row for every 3 columns?

This screenshot is what I got from the code:

This is what I'm looking to get:

Answer 1

Edit: Originally I posted this quickly from the top of my head. Thanks, Wael Assaf for pointing out an improvement, which I have used. Also, I have added a couple of changes to the code, now it is versatile and can be used for a variable number of columns you can choose by changing the variable $numOfCols

You need to add a div for each row. Then the floating divs you have, will not just wrap around but instead will be in their own container.

The bootstrap class row is perfect for this:

Method 1 (not recommended for new versions of HTML and Browser): This method is for older version on HTML and browser because new versions of HTML and browser have inbuild functions to auto close missing tags so when you use code below it will automatically close pre-defined tag <div class="row"> rather than waiting for if condition to close that tag in result causing improper layout.

Note: you can try and observe result by inspecting elements

<?php
//Columns must be a factor of 12 (1,2,3,4,6,12)
$numOfCols = 4;
$rowCount = 0;
$bootstrapColWidth = 12 / $numOfCols;
?>
<div class="row">
<?php
foreach ($rows as $row){
?>  
        <div class="col-md-<?php echo $bootstrapColWidth; ?>">
            <div class="thumbnail">
                <img src="user_file/<?php echo $row->foto; ?>">
            </div>
        </div>
<?php
    $rowCount++;
    if($rowCount % $numOfCols == 0) echo '</div><div class="row">';
}
?>
</div>

Uses PHP modulus operator to echo the open and close of each row at the right points.

Method 2 (recommended): This method is to overcome the problem faced by method 1, as a result, causing proper layout for modern browser.

<?php
//Columns must be a factor of 12 (1,2,3,4,6,12)
$numOfCols = 4;
$rowCount = 0;
$bootstrapColWidth = 12 / $numOfCols;
foreach ($rows as $row){
  if($rowCount % $numOfCols == 0) { ?> <div class="row"> <?php } 
    $rowCount++; ?>  
        <div class="col-md-<?php echo $bootstrapColWidth; ?>">
            <div class="thumbnail">
                <img src="user_file/<?php echo $row->foto; ?>">
            </div>
        </div>
<?php
    if($rowCount % $numOfCols == 0) { ?> </div> <?php } } ?>

Note: you can try and observe result by inspecting elements

Hope this helps.