Core Java: Bitwise Logical Operator

Bitwise operators perform operations on one or two operands on a bit-by-bit basis, as follows, in descending order of precedence.

 

Operator	Description	Usage
~	Bitwise NOT (inversion)	~expr
&	Bitwise AND	expr1 & expr2
^	Bitwise XOR	expr1 ^ expr2
|	Bitwise OR	expr1 | expr2

Expr1	Expr2	Expr1|Expr2	Expr1& Expr2	Expr1^ Expr2
False	False	False	False	False
False	True	True	False	True
True	False	True	False	True
True	True	True	True	False

For ~ operator

~n   -----> - (n+1)

 

Example

 

public class TestBitwiseOp {    public static void main(String[] args) {       int x = 0xAAAA_5555;                // a negative number (sign bit (msb) = 1)       int y = 0x5555_1111;                // a positive number (sign bit (msb) = 0)       System.out.printf("%d%n", x);       // -1431677611       System.out.printf("%d%n", y);       // 1431638289       System.out.printf("%08X%n", ~x);    // 5555AAAAH       System.out.printf("%08X%n", x & y); // 00001111H       System.out.printf("%08X%n", x | y); // FFFF5555H       System.out.printf("%08X%n", x ^ y); // FFFF4444H    } }

Compound operator &=, |= and ^= are also available, e.g., x &= y is the same as x = x & y. 

 

Take note that:

 

·        '&', '|' and '^' are applicable when both operands are integers (int, byte, short, long and char) or booleans. When both operands are integers, they perform bitwise operations. When both operands are booleans, they perform logical AND, OR, XOR operations (i.e., same as logical &&, || and ^). They are not applicable to float and double. On the other hand, logical AND (&&) and OR (||) are applicable to booleans only. 

 

·        System.out.println(true & true);   // logical -> true

 

·        System.out.println(0x1 & 0xffff);  // bitwise -> 1

 

·        System.out.println(true && true);  // logical -> true

 

·        The bitwise NOT (or bit inversion) operator is represented as '~', which is different from logical NOT (!).

 

·        The bitwise XOR is represented as '^', which is the same as logical XOR (^).

 

·        The operators' precedence is in this order: '~', '&', '^', '|', '&&', '||'. 

For example, 

 

      System.out.println(true | true & false);  // true | (true & false) -> true

System.out.println(true ^ true & false);  // true ^ (true & false) -> true