Question

I would like to know what & does in the use case:

7 & 3 
   => 3

8 & 3
   => 0

Or as seen in the general use case:

 Integer & Integer
    => ??

I know that array & array2 gives the intersection between the two arrays, but I am unsure of exactly what is going on here when used with integers.

Answer 1

& is bitwise AND which examines the two operands bit-by-bit and sets each result bit to 1 if both the corresponding input bits are 1, and 0 otherwise. You can also think of it as bit-by-bit multiplication.

     111 (7)
AND  011 (3)
------------
=    011 (3)

    1000 (8)
AND 0011 (3)
------------
=   0000 (0)