bitwise shift operator

Question

Please tell the output ! With explanation..

#include<stdio.h>

int main()
{
 printf("%d", 2<<2>>2);
    printf("\n%d", 2>>2<<2<<(1<<1));
    return 0;
}

Answer 1

'<<' is the bitwise left shift operator - Shifts the bits to left.

'm<<n' shifts the bits of m to the left by n times.

'>>' is the bitwise right shift operator - Shifts the bits to right.

'm>>n' shifts the bits of m to the right by n times.

Say, '2<<3': means shift bits of 2 to left 3 times

Since bit representation of 2 is 00000010

If we shift bits in 2 to left 3 times, we'll get - 00010000

Therefore, 2<<3 =  00010000 = 16

Similarly, '2>>3': means shift bits of 2 to right 3 times

2>>3 = 00000000 = 0

Associativity of bitwise left shift and right shift operators is - left to right.

The output of your program will be:

2
0

Explanation:

In the first printf, '2<<2>>'

is associated like - '((2<<2)>>2)'

Means first left shift bits in 2 by 2 and then right shift by 2, which yields 00000010, i.e 2.

In the second printf, '2>>2<<2<<(1<<1)'

is associated like - '(((2>>2)<<2)<<(1<<1))'

On evaluating this, we'll get 00000000, i.e 0.

Answer 2

Here I am breaking down your question operations working in memory.
Suppose 2 is represented in a byte somewhere in memory.So initial representations are working of shifts and finally printing the value.
In the second printf at some point all bits will be zero and thus performing any bit shift operator would result in zero. !