What does --! do?

[Proville6]

The question is simple: What does --!something at the start of the script do and how to use it?

[falseop_x (jake)]

Luau Type Checking Release

10 months ago, we’ve started upon the journey of helping Roblox scripters write robust code by introducing an early beta of type checking. We’ve received a lot of enthusiastic feedback and worked with the community on trying to make sure critical issues are addressed, usability is improved and the type system is ready for prime time. Today I’m incredibly excited to announce that the first release of Luau type checking is officially released! Thanks a lot to @Apakovtac, @EthicalRobot, @fun_enthu…

[ItsNickBoi110]

--! is used to define typechecking in Luau. You can learn more here.