[SOLVED] Bitwise operators...

[aeonsky]

Even after reading the manual, I have no idea what they are used for and how they produce the result...

 

For example, this...

 

<?php

echo 'this' ^ 'that';
// Produces weird ASCII values

echo 8 ^ 9;
// Produces 1

echo ~'this';
// Produces weird ASCII values

echo 'this' | 'that';
// Produces 'thiw'

?>

 

Could someone explain the operators in more simpler terms?

[DarkWater]

You need to understand binary for these to have any meaning to you whatsoever.  If you don't, I'd suggest pretending that these operators don't exist, but if you want an explanation anyway:

 

Numbers are represented in computers as binary, which is a base 2 system, as opposed to our base 10 decimal system.  This means that the numbers 1, 2, 5, and 128 are represented, for example, like so:

1
10
101
1111111

The bitwise operators operate on each of those bits, or digits, as their own sort of unit.

 

The AND operator (&) returns bits that are set in both numbers.  Using my previous examples, this:

2 & 1

Would give you a result of 3, because the operator works like this:

[pre]

    10

+    1

------

    11

[/pre]

 

The OR (|) operator does the same thing, only it returns bits that are set in either number.

xor (^) only returns ones set in ONE number, but not the other, and NOT (~) flips every bit.

[aeonsky]

Oooh, binary. This makes things a tad easier. Thanks.