Bitwise operators. Differences from javascript and PHP.

John Machin sjmachin at lexicon.net
Fri Nov 17 11:18:57 CET 2006


skoroboga... at gmail.com wrote:
> I can't understand a little thing in bitwise operations.
>
>
> In PHP and Javascript
> 4653896912>>13 = -212992
>
> In Python and Ruby
> 4653896912>>13 = 568102
>
> In Python and Ruby - it's ok. I understand.
> But i need to get in Python same value as in PHP and Javascript.
> How can i do this?

So that someone who knows next-to-nothing about those 2 languages can
help you, what is x >> n defined to do in PHP and Javascript?

If you can answer that question, what part of the Python implementation
of the PHP/Javascript definition are you having trouble with?

If you can't answer it ... is the problem caused by the fact that
4653896912 is, at 9 hex digits, a bit large for a 32-bit integer, those
2 languages don't have longer integers [my guess],
*and*, to quote something I found about PHP while googling,

http://theopensourcery.com/phplogic.htm

"In effect the bitwise operations [words "can be" omitted, I presume]
safely applied to integer variables - their effect on booleans,
float/double or string variables can be predicted but are not really
useful" ???

Cheers,
John




More information about the Python-list mailing list