What do you mean? Format what? A disk?how can I format macOS Mojave?
Sorry, this question doesn’t make any sense. Are you asking how to install Mojave?my computer
The hard drive that has the system on it? Then your computer won’t work. Or a different hard drive? If different, then use Disk Utility, which is an app included in Mojave.I have Mojave installed in my computer and I want to format my computer's hard drive.
Here is the answer:
1. You need a way to boot the Mac using an EXTERNAL drive that is bootable.
2. You then open Disk Utility and "aim it" at the internal drive (topmost item in DU's list, and you MUST first choose "show all devices" from the popup menu (if there is one)
3. You then click the "erase" button and choose "Mac OS extended with journaling enabled".
4. DU will then erase the disk and "format" it.