Bit Manipulation

Question 1

what is a bit?

Answer 1

it’s either 1 or 0

Question 2

what are the bitwise operators?

Answer 2

AND &
OR |
XOR ^
NOT ~
LEFT SHIFT <<
RIGHT SHIFT >>

Question 3

why do we use bit manipulation?

Answer 3

if we want to cram alot of info into one place to improve an algorithm efficiency

Question 4

AND &

Answer 4

only true if both bits are true
1 & 1 = 1
0 & 1 = 0

Question 5

OR |

Answer 5

true if any bit is true
1 & 1 = 1
0 & 1 = 1

Question 6

XOR ^

Answer 6

true if only one bit is true
0 & 1 = 1
1 & 1 = 0

Question 7

NOT ~

Answer 7

one’s complement operator
flips the input bit
~1 = 0
~0 = 1

Question 8

LEFT SHIFT <

Answer 8

Shift the binary digits by n, pad 0’s on the right
each shift is a multiply by 2 unless there is an overflow
00010110
«
00000010 it’s in the second column so it will be shifted by 2 columns
01011000

Question 9

what happens when u left shift out of 8 bits?

Answer 9

some processors throw it away or they wrap around which is called rotation

Question 10

RIGHT SHIFT&raquo_space;

Answer 10

shift binary digits by n, pad 0’s on the left

each shift is a divide by 2 with round towards negative infinity