C++ Primer Plus

The Logical Bitwise Operators

The logical bitwise operators are analogous to the regular logical operators, except they apply to a value on a bit-by-bit basis rather than to the whole. For example, consider the regular negation operator (!) and the bitwise negation (or complement) operator (~). The ! operator converts a true (or nonzero) value to false and a false value to true. The ~ operator converts each individual bit to its opposite (1 to 0 and 0 to 1). For example, consider the unsigned char value of 3:

unsigned char x = 3;

The expression !x has the value 0. To see the value of ~x, you write it in binary form: 00000011. Then you convert each 0 to 1 and each 1 to 0. This produces the value 11111100, which in base 10 is the value 252. (