In C language, bitwise operators are used to perform operations on individual bits of integers. These operators allow direct manipulation of bits, making them useful for tasks such as low-level programming, optimization, and systems programming. Bitwise operations are fast and efficient for various applications like setting, clearing, or flipping particular bits.

List of Bitwise Operators in C

1. Bitwise AND (&):

   • Performs a logical AND operation on each bit of the operands.
   • Resulting bit is 1 only if both bits are 1.
   • Example:

     int a = 5;  // 0101 in binary
     int b = 3;  // 0011 in binary
     int result = a & b;  // 0001 in binary, which is 1
     

2. Bitwise OR (|):

   • Performs a logical OR operation on each bit of the operands.
   • Resulting bit is 1 if at least one bit is 1.
   • Example:

     int a = 5;  // 0101 in binary
     int b = 3;  // 0011 in binary
     int result = a | b;  // 0111 in binary, which is 7
     

3. Bitwise XOR (^):

   • Performs a logical XOR (exclusive OR) operation on each bit of the operands.
   • Resulting bit is 1 if one bit is 1 and the other is 0.
   • Example:

     int a = 5;  // 0101 in binary
     int b = 3;  // 0011 in binary
     int result = a ^ b;  // 0110 in binary, which is 6
     

4. Bitwise NOT (~):

   • Inverts all bits of the operand (changes 1 to 0 and 0 to 1).
   • This is a unary operator (applies to one operand).
   • Example:

     int a = 5;       // 0101 in binary
     int result = ~a; // 1010 in binary (in two's complement representation), which is -6
     

5. Left Shift (<<):

   • Shifts bits of the first operand to the left by the number of positions specified by the second operand.
   • Equivalent to multiplying by 2^n.
   • Example:

     int a = 5;  // 0101 in binary
     int result = a << 1;  // 1010 in binary, which is 10
     

6. Right Shift (>>):

   • Shifts bits of the first operand to the right by the number of positions specified by the second operand.
   • Equivalent to dividing by 2^n (discarding the remainder for integers).
   • Example:

     int a = 20; // 10100 in binary
     int result = a >> 2;  // 00101 in binary, which is 5
     

Bitwise Operator Examples

Here's a complete example of how to use bitwise operators in a C program:

#include <stdio.h>

int main() {
    int a = 6;  // 0110 in binary
    int b = 3;  // 0011 in binary

    printf("a & b = %d\n", a & b);  // 0010 in binary, which is 2
    printf("a | b = %d\n", a | b);  // 0111 in binary, which is 7
    printf("a ^ b = %d\n", a ^ b);  // 0101 in binary, which is 5
    printf("~a = %d\n", ~a);        // 1001 in binary (in two's complement), which is -7
    printf("a << 1 = %d\n", a << 1);  // 1100 in binary, which is 12
    printf("b >> 1 = %d\n", b >> 1);  // 0001 in binary, which is 1

    return 0;
}

Summary of Bitwise Operators:

1. & (AND): Returns 1 if both bits are 1.
2. | (OR): Returns 1 if at least one bit is 1.
3. ^ (XOR): Returns 1 if one bit is 1 and the other is 0.
4. ~ (NOT): Inverts all bits.
5. << (Left Shift): Shifts bits to the left, effectively multiplying by 2^n.
6. >> (Right Shift): Shifts bits to the right, effectively dividing by 2^n.

Important Points:

1. Efficiency: Bitwise operators are highly efficient, particularly in low-level programming, such as working with hardware registers or network protocols.
2. Two's Complement: The ~ operator follows the two's complement representation for negative numbers, which may lead to unexpected results for beginners.
3. Unsigned vs. Signed: For left and right shifts, be careful with signed integers. The right shift for signed values may be implementation-dependent, depending on whether it's arithmetic or logical shift.

Bitwise operators are powerful tools that allow fine control over individual bits, making them essential for certain types of optimizations and low-level programming tasks.