$c = $c ^ 0x82; - any idea what this means?

andrewpeacock

Hi,
I'm trying to figure out how a piece of code works, and it loops though each character in a string and does the above operation.

But I can't search Google for ^ as it doesn't recognise it.!!!

(How did we manage before Google???)

Many thanks all,
Andy

OhLordy

I thought it was going to be to the power of but I can't figure it out

2² = 0
4² = 6
8² = 10
10² = 8
16² = 18
20² = 22

???? You've got me stumped 😕

kilbey1

Well, ^ is the LEFT operator. 0x82 looks like hex code. Perhaps it's trying to tack on or alter something into hex, but your deduction is as good as mine. 🙂

JakesSA

to throw a spanner in the works, Ive come across this equation.

I know how to use it because Ive learnt it like a parriot:


//this will alter between two arrguments
// either or other

$arrgument = ($arr_count% 2) ? $arr1 : $arr2;

Can some please explain the full script to me.

andrewpeacock

Hi all,
^ is XOR - convert the numbers to binary and you'll see that it makes sense.

so...

echo 255 ^ 0xf;

returns 240!

I never thought of just printing out some test data :-)

Thanks all, especially OhLordy!

Andy

Mce

Originally posted by JakesSA
to throw a spanner in the works, Ive come across this equation.

I know how to use it because Ive learnt it like a parriot:
//this will alter between two arrguments
// either or other

$arrgument = ($arr_count% 2) ? $arr1 : $arr2; 
Can some please explain the full script to me. [/B]

Well % is the modulus operator (remainder from a division). So it's dividing $arr_count by 2 and if thier is a remainder (caused by an odd number in this case) it will return $arr1 otherwise it reutnrs $arr2.
BTW I was lightly pondering to make a small function to determine if a number was even or odd so thanks for your question as it answered one floating around in the back of my head.

-Mce

laserlight

Yes, ^ is bitwise XOR in C, C++, PHP and a few other languages.

tomhath

There are ten pages in the manual that cover "operators", it sounds like a few people would do well investing a few minutes reading them (learn about things like tilde, backtick, caret, etc) 🙂

http://www.phpbuilder.com/manual/language.operators.php