title: How to display an image if variable equals a special number using swift 3?
body: <p>I have three pictures (<code>lvl1.png, lvl2.png, lvl3.png</code>) and an variable (<code>let level = 1</code>). What should I do to display an image named 'lvl2' if <code>level = 2</code>, and when <code>level = 3</code> I need to show the last image (lvl3.png)?</p>