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Added examples for logic operators (#22259)

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* Added examples for logic operators

Added tables for examples for "and", "or" and "xor"

* fixed table formatting
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Krinjih
2018-11-19 03:51:17 +01:00
committed by Christopher McCormack
parent 5553ba0c53
commit 68e7028aab
1 changed files with 24 additions and 0 deletions
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guide/english/c/more-math/index.md
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@ -42,15 +42,39 @@ Because C is low level as mentioned before, you have access to the individual bi
### AND
`c = a & b;` will perform a bitwise AND. This means that if the first bit of `a` and the first bit of `b` are both 1, the first bit of c will be 1, and 0 otherwise. If the second bit of `a` and `b` are both 1, the second bit of c will be 1, and 0 otherwise. This goes on until all bits have been and'd.
Example:
| Bit | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|:-----:|---|---|---|---|---|---|---|---|
| a | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 |
| b | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 1 |
| a & b | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 0 |
### OR
`c = a | b;` will perform a bitwise OR. The first bit of `c` is 1 if the first bit in either `a` or `b` is 1, the second bit is 1 if the second bit in either `a` or `b` is 1, and so on.
Example:
| Bit | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|:------:|---|---|---|---|---|---|---|---|
| a | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 |
| b | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 1 |
| a \| b | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 |
### NOT
`b = ~a;` will set `b` to the one's complement of `a`, meaning that any 1 becomes a 0 and any 0 becomes a 1.
### XOR
`c = a ^ b;` will perform a bitwise XOR. This is an exclusive or, meaning that the first bit of `c` is 1 if either `a` or `b` is 1, but not both. The second bit is 1 if either is 1 but not both, and so on.
Example:
| Bit | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|:-----:|---|---|---|---|---|---|---|---|
| a | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 |
| b | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 1 |
| a ^ b | 0 | 1 | 1 | 0 | 0 | 1 | 0 | 1 |
### Shift
A bitwise shift will take the bits and move them to some number of places to the left or right. For example, say we have a set of bits: `101110`. C performs an arithmetic shift when bit shifting. Let's use a table to make that more clear: