# & - bitwise AND

suggest change
``````#include <iostream>

int main(int argc, char **argv) {
int a = 6;     // 0110b  (0x06)
int b = 10;    // 1010b  (0x0A)
int c = a & b; // 0010b  (0x02)

std::cout << "a = " << a << ", b = " << b << ", c = " << c << std::endl;
}``````
``````a = 6, b = 10, c = 2
``````

Why

A bit wise `AND` operates on the bit level and uses the following Boolean truth table:

``````TRUE  AND TRUE  = TRUE
TRUE  AND FALSE = FALSE
FALSE AND FALSE = FALSE``````

When the binary value for `a` (`0110`) and the binary value for `b` (`1010`) are `AND`’ed together we get the binary value of `0010`:

``````int a = 0 1 1 0
int b = 1 0 1 0 &
---------
int c = 0 0 1 0``````

The bit wise AND does not change the value of the original values unless specifically assigned to using the bit wise assignment compound operator `&=`:

``````#include <iostream>

int main(int argc, char **argv) {
int a = 5;  // 0101b  (0x05)
a &= 10;    // a = 0101b & 1010b == 0

std::cout << "a = " << a << std::endl;
}``````
``````a = 0
``````