title: Understanding UIScrollView Constraints
body: <p>I have a <code>UIScrollView</code> with a <code>UIView</code> inside it and 3 <code>UITableViews</code> inside the view and I have the following constraints for the view : </p>
  
  <p><a href="https://i.stack.imgur.com/2TueM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2TueM.png" alt="enter image description here"></a></p>
  
  <p>In my code, exactly in <code>ViewDidLayoutSubviews</code> I have the following code </p>
  
  <pre><code>- (void)viewDidLayoutSubviews {
      [_containerScrollView setContentSize:CGSizeMake(SCREEN_WIDTH * 3, [_containerScrollView frame].size.height)];
  
      [_contentViewWidthLayoutcontraint setConstant:SCREEN_WIDTH * 3];
      [[self view] layoutIfNeeded];
  }
  </code></pre>
  
  <p>Which change the view width realtivly to the screen width.</p>
  
  <p>My question is <strong>why there is no conflict between the width constraint and the leading/trailing constraints ?</strong></p>