Convert Mysql select query loop for values into PDO loop

I have been doing MYSQL just fine for a while now but am trying to learn how to do all that i know with PDO; what I am struggling with now is a simple SQL select, and then I loop through all the rows and dump the corresponding column values into a variable; and then I can do something with the variables for that row while in the loop; here is the way I used to do it with mysql:

$result42 = mysql_query("SELECT * FROM members");

while($row = mysql_fetch_array($result42, MYSQL_BOTH))
{
$user_id=$row['user_id'];
$user_name=$row['user_name'];
$email=$row['email'];

// do something with info for each user; like maybe echo their info...
}

I am attempting to do the same thing with PDO but not finding anything quite like what I am trying to do…

I found some code which uses fetchall and fetchassoc and seems to be putting it in an array; but I have no idea how to loop through the array and get each value on the row like i did with mysql above; and I am not even sure if the PDO that i have here can do that…

this is what I have:

$stmt = $dbh->prepare("SELECT * FROM members");

$products = array();
if ($stmt->execute()) {
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    $products[] = $row;
}
}

All i want to do is end up cycling through each row getting the values, doing something with them and then moving on to the next row…

Can anyone help with this? Thanks...