Does a variable take up any memory after it is declared?

Question

C++ / C#

int x;
Does this variable take up memory?

Answer 1

1) not identified, but not initialized.
2) in this case, the memory is allocated on the stack.

Answer 2

Depends on the compiler. I’ll tell you more, only static variables definitely occupy memory, any others can be register

Answer 3

intx;
Does this variable take up memory?

It takes about 6 bytes per entry in the code.
When compiling to an executable file, the compiler will remove it the fastest (depending on optimization settings)