Question: Both A and B UIView are inside scrollView. As you can see in the image UIView B isn't filling and fit to the bottom of the 5.5 screens. Is there is any solution to automatically grow the UIView B to fit to screen bottom.
[![enter image description here](https://i.stack.imgur.com/WB5Lc.png)](https://i.stack.imgur.com/WB5Lc.png)

Answer: 
First, if your views have a set size, I would recommend rethinking putting them in a scrollview. 

If you have a reason for it, your best option to do it automatically would likely be adding constraints for equating the height of the ViewController's view to A and B views.

The more flexible solution would be to handle it in your ViewController code with references to the height constraints of the views. Something like:

```
if (aViewHeightConstraint.constant + bViewHeightConstraint.constant) < desiredHeight {
    bViewHeightConstraint.constant += (aViewHeightConstraint.constant + bViewHeightConstraint.constant) - desiredHeight
    self.view.setNeedsLayout()
    self.view.layoutIfNeeded()
}

```

that's uncompiled, but it should get you down the right path.
I just remove the existing height constraint, add a new height to match the remain space

```
 let hightConstraint = getConstraint(viewFollowMe, constaintId: "constriantHeightFollowMe")

        if hightConstraint != nil {
            viewFollowMe.removeConstraint(hightConstraint!)

            let heightContraints = NSLayoutConstraint(item: viewFollowMe, attribute:
                .Height, relatedBy:.GreaterThanOrEqual , toItem: nil,
                attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1.0,
                constant: VIEW_HEIGT_BOTTOM)
            viewFollowMe.addConstraint(heightContraints)
        }

```