Add a variable to a variable
<p>Sorry for a misleading title, was hard to explain the problem so short...</p>

<p>So I've got a few variables named <code>$exp_lvl1</code>, <code>$exp_lvl2</code> and so on...</p>

<p>To make it more simple I got <code>$exp_lvl</code> (which just gives an error because it don't exist and that's normal in this case) and I got the number needed in a variable <code>$next_exp</code>.</p>

<p>How do I put these together? I have tried <code>$exp_lvl.$next_exp</code> and it didn't work. How should I do? </p>
