How do I return a string that builds a new table row each time a function is called in PHP?

I have created a function in PHP that is supposed to "return a string that builds a new table row each time it is called" . I've tried searching for how to do this but I'm unsure. Can anyone provide assistance ? My code for the function that I built is below:

<?php
//Creating the function returnRow().
function returnRow($counter, $quantity) 
{
    $ticketprice = 50;

    if($quantity >= 300)
    {
        $ticketprice = 30;
    }
    else if ($quantity >= 200)
    {
        $ticketprice = 35;
    }
    else if ($quantity < 200)
    {
        $ticketprice = 50;
    }

    //The return statement will go here but I do not know how to create it.
   //it will return a new html table row.
}

?>
Copy code