Bitwise operation Inverse (~) with (&) XOR (^) or (|) Move right (>>) shift Left (<<)

first know the characteristics of these two binary data: 1=0000 0000 0000 0000 0000 0000 0000 0001

-1=1000 0000 0000 0000 0000 0000 0000 0001

1. The highest position (first) is positive or negative (0 is positive, 1 is negative)

2. Lowest bit (bottom) indicates parity (0 is even, 1 is odd)

One, bitwise reverse (~)

Decimal 1 bitwise reversed =?

Analysis:

1. Decimal 1 into binary: 1 = 0000 0000 0000 0000 0000 0000 0000 0001

2. bitwise REVERSE : The original binary system to get a new binary, the original is 0 is changed to 0.

1 bitwise inversion gets 1111 1111 1111 1111 1111 1111 1111 1110

3. The highest digit of the binary (first) is positive or negative (1 is negative, 0 is positive), if it is negative, if it is negative, it needs to be represented by the complement of the computer.

complement : complement = sign bit (highest bit) after bitwise inversion plus 1.

complement 1000 0000 0000 0000 0000 0000 0000 0010

4. The result is: the complement is converted to decimal:-2;

~1==-2

Decimal-1 bitwise reversed =?

1.-1 of the binary is 1000 0000 0000 0000 0000 0000 0000 0001

2. Negative numbers are stored in the form of their complement .

1 stored in the computer is 1111 1111 1111 1111 1111 1111 1111 1111

3. Bitwise REVERSE: 0000 0000 0000 0000 0000 0000 0000 0000

4. The result is: decimal: 0

~-1==0

Ii. bitwise AND AND (&)

Bitwise AND and (&): Two digits of the same bit are 1, or 1; if one is not 1, then 0.

25&3=> 25 = 0000 0000 0000 0000 0000 0000 0001 1001

3= 0000 0000 0000 0000 0000 0000 0000 0011

-------------------------------------------------------------------------------------

0000 0000 0000 0000 0000 0000 0000 0001

25&3==1

Third, bitwise XOR or (^)

Bitwise XOR (^): The same bit differs by 1 and the same is 0

25^3=> 25 = 0000 0000 0000 0000 0000 0000 0001 1001

3= 0000 0000 0000 0000 0000 0000 0000 0011

-------------------------------------------------------------------------------------

0000 0000 0000 0000 0000 0000 0001 1010

25&3==26

Four, bitwise OR (|)

Bitwise OR (|): The same bit as long as one is 1 is 1.

25|3=> 25 = 0000 0000 0000 0000 0000 0000 0001 1001

3= 0000 0000 0000 0000 0000 0000 0000 0011

-------------------------------------------------------------------------------------

0000 0000 0000 0000 0000 0000 0001 1011

25|3==27

v. Right SHIFT (>>)

Shift the position of 1 to the right n, and leave it out.

15=0000 0000 0000 0000 0000 0000 0000 1111

15>>1=0000 0000 0000 0000 0000 0000 0000 0111

15>>1=7

: The right shift is 1 bits divided by 21, and rounded.

n>>4==n/(24)

64>>4==4

VI. Shift Left (<<)

Shift the position of 1 to the left N, and leave it out.

: 1 bits to the left is multiplied by 21, and rounded.

N<<4==n*24

2<<4==32

Bitwise operation Inverse (~) with (&) XOR (^) or (|) Move right (>>) shift Left (<<)