No Autolayout needed when we put two splashes of 640 x 960 and 640 x 1136 dimension

Question

I have today experienced something weird. Here's what I did. I just created a new project and added a new launch set in image.xcassets. I am using Xcode 6.4

There I only used two splashes

1. 640 X 960
2. 640 X 1136

Then I just made a view with two text fields and label in the middle. I didn't put any constraint and built my UI on any x any size class dimension and 4 inch view

The preview which I saw is wrong as I have not set any constraints

But When I ran the app in various devices and simulators (4s 5s 6 6plus) The labels and textfields were exactly in the center as they are shown in the 4inch or 3.5 inch figure.

Later I also added the 750x1334 launch image in my image.xcassets and that made the difference. The preview which I posted is now behaving exactly the same in every device. But again I removed this splash 750x1334 and everything again seems to be fixed without any single constraint. Has anyone tried that thing. What can be the problem and a solution for that or this is a bug in xcode?

Answer 1

If you don't provide splash for 6 and 6+ then your app will run in Scale Mode

What it does?
Scale mode scales your 4 inch screen in 4.7 and 5 inch screen.

You can read Getting Started section of this article for more. This was done so that the apps on the apps store (before the launch of 6 & 6+) should run on newer devices without updating the apps.