Hide button in Swift 3
<p>I've just started with coding and I really want to know how to hide buttons.</p>

<p>What I want to do is when I press my button:</p>

<p><strong>Start:</strong> I want to let the start button and the back button disappear.</p>

<p>It's done with Outlets and Actions.</p>

<p>I already searched a bit but when I wanted to do it, it said that the <code>do</code> keyword is expected to designate a block of statements.</p>

<p>I hope someone can help me out.</p>