title: how to set constraint for uicollectionview so that it adjusts with all devices
body: <p><a href="https://i.stack.imgur.com/RYXiI.png" rel="nofollow noreferrer">enter image description here</a>/Users/seedoo/Desktop/Simulator Screen Shot 28-Jul-2017, 1.33.59 PM.png
  /Users/seedoo/Desktop/Simulator Screen Shot 28-Jul-2017, 1.34.37 PM.png</p>
  
  <p>The gaps between the cells is less in iPhone 5s device than in 6s.Please let me know how to solve this issue.Thanks in advance.</p>