How to add UIScrollView Constraints

1. Drag UIScrollView to storyboard
2. Add leading, trailing, top, bottom of UIScrollView
3. Add UIView Inside UIScrollView & Rename it to scrollContainerView
4. Add leading, trailing, top, bottom of UIScrollView with parent UIScrollView
5. Add Equal Width content of scrollContainerView with respect to UIScrollVIew
6. Add objects to the scrollContainerView – i have added two button make sure leading trailing top & bottom is set with respect to the scrollContainerView
7. Make sure the to add last item(UIButton) constraint to bottom of the scrollContainerView

The Source code is here 

Note: If you need horizontal scroll make  scrollContainerView equal height constraint with UIScrollView

Here is the Youtube video of the same process. —