We define a function outside of the main function so how is it that we use it inside the main function?

Question

Hello guys. The question is complete in the title but i have another thing to ask too.
Is it possible to define a function inside another function so that it can only be called inside of that?

Answer 1

Ok im sorry i thought it would kinda be concluded

Answer 2

what language ? most of them no.
javascript can have a nested function.
other than that, maybe by using class and private method