What are bitwise operators?

Question

I\'m someone who writes code just for fun and haven\'t really delved into it in either an academic or professional setting, so stuff like these bitwise operators really esca

Answer 1

In digital computer programming, a bitwise operation operates on one or more bit patterns or binary numerals at the level of their individual bits. It is a fast, primitive action directly supported by the processor, and is used to manipulate values for comparisons and calculations.

operations:

• bitwise AND

• bitwise OR

• bitwise NOT

• bitwise XOR

• etc

List item

    AND|0 1        OR|0 1 
    ---+----      ---+---- 
      0|0 0         0|0 1 
      1|0 1         1|1 1 

   XOR|0 1        NOT|0 1 
   ---+----       ---+--- 
     0|0 1           |1 0 
     1|1 0

Eg.

    203: 1100 1011
AND  15: 0000 1111
------------------
  =  11: 0000 1011

Uses of bitwise operator

• The left-shift and right-shift operators are equivalent to multiplication and division by x * 2^y respectively.

Eg.

int main()
{
     int x = 19;
     printf ("x << 1 = %d\n" , x <<1);
     printf ("x >> 1 = %d\n", x >>1);
     return 0;
}
// Output: 38 9

• The & operator can be used to quickly check if a number is odd or even

Eg.

int main()
{
    int x = 19;
    (x & 1)? printf("Odd"): printf("Even");
    return 0;
 }
// Output: Odd

• Quick find minimum of x and y without if else statement

Eg.

int min(int x, int y)
{
    return y ^ ((x ^ y) & - (x < y))
}

• Decimal to binary conversion

Eg.

#include 
int main ()
{
    int n , c , k ;
    printf("Enter an integer in decimal number system\n " ) ;
    scanf( "%d" , & n );
    printf("%d in binary number
    system is: \n " , n ) ;
    for ( c = 31; c >= 0 ; c -- )
    {
         k = n >> c ;
         if ( k & 1 )
              printf("1" ) ;
         else
              printf("0" ) ;
      }
      printf(" \n " );
      return 0 ;
}

• The XOR gate encryption is popular technique, because of its complixblity and reare use by the programmer.
• bitwise XOR operator is the most useful operator from technical interview perspective.

bitwise shifting works only with +ve number

Also there is a wide range of use of bitwise logic