Performs a bitwise AND on two expressions.
result = expression1 & expression2
The & operator looks at the binary representation of the values of two expressions and does a bitwise AND operation on them. The result of this operation behaves as follows:
0101 (expression1) 1100 (expression2) ---- 0100 (result)
Any time both of the expressions have a 1 in a digit, the result has a 1 in that digit. Otherwise, the result has a 0 in that digit.