How can a variable be used when its definition is bypassed?

Question

In my mind, always, definition means storage allocation.

In the following code, int i allocates a 4-byte (typically) storage on program stack and bind

Answer 1

To make it short, variable declaration is lexical, i.e. pertaining to the lexical {}-enclosed blocks. The binding is valid from the line it is declared to the end of the block. It is unaffected by flow control (goto).

Variable assignment of locol (stack) variables, on the other hand, is a runtime operation performed when the control flow gets there. So goto has an influence on that.

Things get a bit more tricky when object construction becomes involved, but that's not your case here.