Intellij shortcut to convert code to upper or lower case?

Ctrl + Shift + U

In the future try typing: Ctrl + Shift + A and look for any actions you like. Here: Toggle Case.

Or ⌘ Command + Shift + U if you are using Mac OSX.

According to the documentation :

Ctrl + Shift + U : Toggle case of the selected text block

I would highly recommend String Manipulation plugin for Intellij.

With a simple Alt + M (Option + M for Mac) you get:

https://i.stack.imgur.com/n716m.png

So you can easily manipulate with strings in the following way:

https://i.stack.imgur.com/aUU7n.gif

If you are an Ubuntu User you will notice that Ctrl + Shift + U will add an u instead of toggling the case.

The solution for me was to change the KeyMap from:

Ctrl + Shift + U --> Alt + Shift + U

You can do so with this Docs

Please check your hot-key settings first. You could go to

File > Settings > Search for Keymap > Search for Toggle Case

and see what hot-key has been configured. See screenshot below:-

https://i.stack.imgur.com/dyDCC.png

If not configured, create a new one for yourself.

Select the text/word/line to be modified and hitting Cntrl+Shift+U or Command+Shift+U` (MAC) works. Please look here for more detail

Toggle case in Intellij IDE:

For Ubuntu OS use Ctrl+Shift+x or Ctrl+Shift+y

For Windows OS use Ctrl+Shift+u