正确输出php数组到html代码

I have this piece of code where I need to output some $_POST values into HTML. Nothing happens in the output line (see comment inside the code), even though var_dump() shows that the needed values are in the array and under the desired indexes.

The trick is that the array indexes for the required data depend on the counter $i. I'm feeling like there is some really stupid and basic syntax mistake in this code. Please help me, oh almighty Hivemind!

while ($i < $somespecificvar) 
{ 
    if (($i != 0) AND ($i < $somespecificvar)) 
    {
        echo "
<td></td>
";
    }

    echo "<td>";

    if ($_POST["text_l$i"] != 0)
    {
        echo "{$_POST['text_l$i']}, {$_POST['l$i']}";// NOTHING HAPPENS OVER HERE
    }

    echo "</td>";
    $i++;
}

In PHP, you can use the {$variable} inside a "" string, however it can only really handle basic variables. Change it so it's like so:

echo $_POST['text_l' . $i] . ', ' . $_POST['l' . $i];