C Programming - Bitwise Operators - Discussion

Bit-wise AND operator is able to mask a particular bit.

Eg: Let us take 15 (decimal).
--->1111 (binary).

If we want 3rd bit only then simply mask the given number with 1000 by using bit-wise AND.
1111 (given number).
1000 (3rd-bit mask value).

---- - (bit-wise AND operation).
1000 (required result).

! operator makes the non zero number into zero.
thus (!52)=0,!65=0,...........
but ! (0)=1
why don't the answer is ! operator?

Can anyone explain?

Thanks all for explaining this.

how to work & operator in the program?

Can anyone explain with an example, please?

AND.

0 & 0 = 0 OFF.
1 & 0 = 0 OFF.

OR.

X & 0 = 0 OFF.

OR.

Input & 0 = 0 OFF.

BUT OR.

0| 0 = 0.
0| 1 = 1.
1| 0 = 1.
1| 1 = 1.

You can't OFF a 1 (input).

As you can see above.

Bitwise AND operator (&), one's complement operator(~)

Example: To unset the 4th bit of byte_data or to turn off a particular bit in a number.

Explanation: Consider, Material from Interview Mantra. Subscribe to free updates via email.

char byte_data= 0b00010111;byte_data= (byte_data)&(~(1<<4));

1 can be represented in binary as 0b00000001 = (1<<4)

<< is a left bit shift operator,

It shifts the bit 1 by 4 places towards left.

(1<<4) becomes 0b00010000

And ~ is the one's complement operator in C language.

So ~(1<<4) = complement of 0b00010000

= 0b11101111

Replacing value of byte_data and ~(1<<4) in (byte_data)&(~(1<<4));

We get (0b00010111) & (0b11101111)

Perform AND operation to below bytes.

00010111

11101111

-----------

00000111

-----------

Thus the 4th bit is unset.

Any bit AND(&) with 0 will give a zero .i.e. will turn that particular bit OFF.

For an example:

int a,b,c;
a=5;
b=6;
c=a&&b;

//In this situation when a and b having any -ve or +ve value.

Then it is taken as 1. So c = 1 && 1=1. Rather then '0' all value are taken as 1.

d = a & b; //In this situation the operation is perform between every binary bit of a and b. So a = 5 = 101.

b = 6 = 110 so d = 100 = 4.

That is why '&&' called logical operator and '&' called bit-wise operator.

If we read question carefully what I understood is that if I want to turn off the bit.

i.e First bit is on means 1. To turn off it I use negation so that it will turn off.

I think ^ operator.