Why do I have to set the dataSource and delegate to self? : <p>I'm learning swift, and the course I'm following teaches tableViews. It I have to set the <code>TableViewController</code> t include <code>UITableViewDataSource</code> and <code>UITableViewDelegate</code>. Then, in <code>viewDidLoad</code>, I have to set </p>

<pre><code>tableView.dataSource = self
tableView.delegate = self
</code></pre>

<p>in order for the tableView to appear and load data. </p>

<p>Why do I have to do this?</p>
