title: Difference between layoutSubviews() and viewWillLayoutSubviews()
body: <p>I understand that <code>layoutSubviews()</code> is a method in <code>UIView</code> and <code>viewWillLayoutSubviews()</code> is a method in <code>UIViewController</code>, they are both used to adjust the position of the subviews when the bounds/frame changes, but I'm not exactly sure the difference between them and when to use them. Could someone please enlighten me? </p>