OK, so generally a form field without a label is a big no no. Relying only on a placeholder or a default value to portray the information required is usually a bad idea. There is a good post, ironically titled Always use a label, which gives some good detail on the issues.

So if you should always use a label why am I about to suggest a situation where labels could be dropped?

No labels

Well, it’s actually a very specific situation... a login form.

A login form is usually instantly recognisable. …

In my latest iOS project I have discovered the power of size classes.

Adaptivity is the key to why this feature exists. A single layout file can be used for multiple device sizes without any code changes to adapt to different screen sizes.

make it even easier to adapt your user interface to any size or orientation.

https://developer.apple.com/design/adaptivity/

Previously I would add and remove constraints in the code behind depending on checks for screen width and height. How annoying! But now I can handle those constraint changes within the layout file in Xcode. How convenient!

How it works