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| id | tags | created | |
|---|---|---|---|
| t127 |
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Saturday, April 20, 2024 |
Bitwise operators
In addition to mathematical, logical and comparison operators, there are bitwise operators. These operators execute conditions based on the actual bits of a value rather than the values that the bits are encoded to represent.
Bitwise operators are typically represented with single characters of existing
operators, e.g. & instead of &&:
| Bitwise operation | Operator |
|---|---|
| AND | & |
| OR | (single pipe) |
| NOT | ~ |
An example of using the & operator:
x = 5
y = 3
a = x & y
b = x | y
The value of a will be 1. The reason is we are looking at the bit values of
x and y and then applying Boolean AND to each bit:
x = 5 = 0101
y = 3 = 0011
a = 1 = 0001
Working from right to left for each column:
- true and true = true
- false and true = false
- true and false = false
- false and false = false
This leaves us with 0001 which is equal to 1 in binary and denary.
For the case of bitwise OR we get 7 as the result of x | y:
x = 5 = 0101
y = 3 = 0011
b = 7 = 0111
- true or true = true
- false or true = true
- true or false = true
- false or false = true
This leaves us with 0111 which is equal to 7 in denary.
Why use them?
Bitwise operations are more of a hallmark of lower-level programming. As bit operations are the fastest and lowest level of computation, being able to directly access and operate on bits within a programming language can be beneficial when efficiency and speed of execution is a factor or when memory is constrained.