Question

1. What is value of X after following operation

int X=0x 45;

X = X<<3 ; X=

What is value of X after following operation

int x=0x 40;

X = X>>3 ; X=

What is value of X after following operation

int x=0X FF;

X = X & 0x0F; X=

What is value of X after following operation

int x=0x FF;

X = ~X ; X=

What is value of X after following operation

int X=0x FF;

X = X &~(1<<4) ; X=

Answer 1

Literals that start with 0x are hexadecimal integers .

4 in binary = 0100

5 in binary = 0101

means 0x45 = 0100 0101

so int x =0x45 means in binary x will contain 0100 0101(with some preceding zeros according to compiler beacuse interger can take 32 or 64 bit according to compiler)

1.

int x= 0x45;

x=x<<3;

/*

given x =0000 0000 0000 0000 0000 0000 0100 0101

<< is left shift operator means we have to shift 3 bits towads left with inserting three extra zeros to right

takin 32 bit for integer

after applying bitwise left shift operator , shifting each bit to left by 3 bits

x= 0000 0000 0000 0000 0000 0010 0010 1000 = 552(in decimal number system)

*/

x= 552 // final answe

2.

int x= 0x40;

x=x>>3;

/*

x =0x40 means in binary x will contain 0100 0000(with some preceding zeros according to compiler beacuse interger can take 32 or 64 bit according to compiler)

given x =0000 0000 0000 0000 0000 0000 0100 0000

>> is right shift operator means we have to shift 3 bits towads right with inserting three extra zeros to left

takin 32 bit for integer

after applying bitwise right shift operator , shifting each bit to right by 3 bits

x= 0000 0000 0000 0000 0000 0000 0000 1000   = 8(in decimal number system)

*/

x= 8 // final answer

3.

int x=0X FF;

X = X & 0x0F;

/*

x =0xFF means in binary x will contain 1111 1111(with some preceding zeros according to compiler beacuse interger can take 32 or 64 bit according to compiler)

given x =0000 0000 0000 0000 0000 0000 1111 1111

& is bitwise AND operator, means we have to do bitwise anding (only 1&1=1, otherwise 0 for all cases)

x = 0000 0000 0000 0000 0000 0000 1111 1111

0x0F= 0000 0000 0000 0000 0000 0000 0000 1111 ( execute bitwise and for each bit)

X =   0000 0000 0000 0000 0000 0000 0000 1111

x= 0000 0000 0000 0000 0000 0000 0000 1111   = 15(in decimal number system)

*/

x=15 // final answer

4.

int x=0x FF;

X = ~X ;

/*

x =0xFF means in binary x will contain 1111 1111(with some preceding zeros according to compiler beacuse interger can take 32 or 64 bit according to compiler)

given x =0000 0000 0000 0000 0000 0000 1111 1111

x= 255 (in decimal)

~ is bitwise NOT operator, means we have to do bitwise negation of x;

simply in short ~x means -(x+1)

so here x= 255(in decimal)

after applying ~operator

x= -256;

*/

x= -256 // final answer

5.

X=0x FF;

X = X &~(1<<4) ;

/*

x =0xFF means in binary x will contain 1111 1111(with some preceding zeros according to compiler beacuse interger can take 32 or 64 bit according to compiler)

given x =0000 0000 0000 0000 0000 0000 1111 1111

1<<4 is 0000 0000 0000 0000 0000 0000 0001 0000 =(16 in decimal)

~ is bitwise NOT operator, means we have to do bitwise negation of x;

simply in short ~x means -(x+1)

so here ~(1<<4)= ~(16)= -17

x=x&~(1<<4); // apply bitwise and now

x=239;

*/

x= 239 // final answer