RE: [PHP] RE: Bitwise operator question

Thanks Philip, OK I understand the binary thing but that line, I just don't see it, It's not the or operator that's summing up the two binary values is it? Dan -----Original Message----- From: Philip Hallstrom [mailto:philip@adhesivemedia.com] Sent: Monday, March 03, 2003 3:53 PM To: Dan Sabo Cc: php-general@lists.php.net Subject: [PHP] RE: Bitwise operator question Yes. Oops. -philip On Mon, 3 Mar 2003, Dan Sabo wrote: > Hi Phillip, > > Don't U mean > > 0001 > | 0100 > = 0101 > > ? > > Dan > > -----Original Message----- > From: Philip Hallstrom [mailto:philip@adhesivemedia.com] > Sent: Monday, March 03, 2003 2:33 PM > To: Dan Sabo > Cc: php-general@lists.php.net > Subject: Re: Bitwise operator question > > > Here's how I think about it... > > CREATE_RECORDS = 1 in decimal and 0001 in binary. > ALTER_RECORDS = 4 in decimal and 0101 in binary. > > that line returns a binary string where *any* of the bits are 1, so line > them up: > > 0001 > | 0101 > = 0101 > > which is 5. > > On Mon, 3 Mar 2003, Dan Sabo wrote: > > > Hi, > > > > I'm reading the description of Bitwise Operators on page 81 of > "Professional > > PHP 4", the Wrox book. In the highlighted example on that page, the line > of > > code... > > > > $user_permissions = CREATE_RECORDS | ALTER_RECORDS; > > > > the description in the book says that this line is building a set of user > > permissions out of the previously created constants with the OR operator > (I > > understand what OR means). The value of $user_permissions is set to > either > > 1 or 4, which is in fact 5 (0101). But how is this single line doing > that? > > The explanation was cryptic (to me). > > > > > > > > -- > > PHP General Mailing List (http://www.php.net/) > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php