How to move the value of a first variable to another (second) variable in which the first variable will become empty or 0 value.

Question

And the other(Second)variable will contain the value of the first variable.
Ex:
Original Values
int A=20;
int B;

Moved Values(Output of code)
int A; or int A=0;
int B=20;

Answer 1

int A = 20;
int B = A;
A=0;

Answer 2

Thanks bro