A2oz

What are the four bitwise operators used in C with examples?

Published in Programming Languages 3 mins read

C programming language provides several operators for manipulating data at the bit level. These bitwise operators work on individual bits of data, allowing you to perform efficient operations on binary representations of numbers. Here are four commonly used bitwise operators in C, along with illustrative examples:

1. Bitwise AND (&)

The bitwise AND operator compares corresponding bits of two operands. If both bits are 1, the resulting bit is 1; otherwise, it's 0.

Example:

int a = 5; // Binary: 00000101
int b = 3; // Binary: 00000011
int result = a & b; // Binary: 00000001 (Decimal: 1)

Practical Insights:

  • Clearing bits: You can use the bitwise AND operator to clear specific bits in a number. For example, to clear the second bit of a (00000101), you can AND it with 00000111 (decimal 7).
  • Checking if a bit is set: You can check if a specific bit is set by ANDing the number with a mask containing only that bit. For example, to check if the third bit of a is set, you can AND it with 00000100 (decimal 4).

2. Bitwise OR (|)

The bitwise OR operator compares corresponding bits of two operands. If at least one bit is 1, the resulting bit is 1.

Example:

int a = 5; // Binary: 00000101
int b = 3; // Binary: 00000011
int result = a | b; // Binary: 00000111 (Decimal: 7)

Practical Insights:

  • Setting bits: You can use the bitwise OR operator to set specific bits in a number. For example, to set the third bit of a (00000101), you can OR it with 00000100 (decimal 4).
  • Combining flags: You can use bitwise OR to combine multiple flags into a single variable. Each bit represents a different flag, and you can set or clear them individually.

3. Bitwise XOR (^)

The bitwise XOR operator compares corresponding bits of two operands. If the bits are different, the resulting bit is 1; otherwise, it's 0.

Example:

int a = 5; // Binary: 00000101
int b = 3; // Binary: 00000011
int result = a ^ b; // Binary: 00000110 (Decimal: 6)

Practical Insights:

  • Swapping values: You can swap two variables without using a temporary variable using bitwise XOR.
  • Error detection: XOR is used in error detection and correction schemes like parity bits and checksums.

4. Bitwise NOT (~)

The bitwise NOT operator flips the bits of an operand. A 1 becomes 0, and a 0 becomes 1.

Example:

int a = 5; // Binary: 00000101
int result = ~a; // Binary: 11111010 (Decimal: -6)

Practical Insights:

  • Negating numbers: The bitwise NOT operator can be used to negate a number.
  • Creating masks: You can use bitwise NOT to create masks for various bit manipulation operations.

Conclusion:

Bitwise operators are powerful tools in C for manipulating data at the bit level. They allow you to perform efficient operations like setting, clearing, and checking individual bits, making them essential for tasks involving binary representations, error detection, and low-level programming.

Related Articles