Doc #52069 [Opn]: DateTime::sub( ), DateTime::add( ), etc...

Edit report at http://bugs.php.net/bug.php?id=52069&edit=1 ID: 52069 Updated by: derick@php.net Reported by: wdolek at gmail dot com Summary: DateTime::sub( ), DateTime::add( ), etc... Status: Open Type: Documentation Problem Package: Documentation problem Operating System: Fedora 12, 2.6.32.11-99 PHP Version: 5.3.2 New Comment: The reason why it returns the instance, is so that you can do for example: $d->add("+2 days")->modify("next weekday")->sub("1 month"); Previous Comments: ------------------------------------------------------------------------ [2010-06-12 22:05:04] wdolek at gmail dot com Description: ------------ http://www.php.net/manual/en/datetime.sub.php documentation says: DateTime::sub — Subtracts an amount of days, months, years, hours, minutes and seconds from a DateTime object Return Values Returns the modified DateTime object or FALSE on failure. this is fine, but it is not clear that "sub" or "add" modify value on called instance, and then - really dont know why - returns that instance (again). Test script: --------------- $d1 = new DateTime(); $d2 = $d1->sub(new DateInterval('P1W')); var_dump($d1); var_dump($d2); var_dump($d1 === $d2); Expected result: ---------------- object(DateTime)[1] public 'date' => string '2010-06-12 22:01:55' (length=19) public 'timezone_type' => int 3 public 'timezone' => string 'Europe/Wdoltown' (length=13) object(DateTime)[2] public 'date' => string '2010-06-05 22:01:55' (length=19) public 'timezone_type' => int 3 public 'timezone' => string 'Europe/Wdoltown' (length=13) boolean false Actual result: -------------- object(DateTime)[1] public 'date' => string '2010-06-05 22:01:55' (length=19) public 'timezone_type' => int 3 public 'timezone' => string 'Europe/Wdoltown' (length=13) object(DateTime)[1] public 'date' => string '2010-06-05 22:01:55' (length=19) public 'timezone_type' => int 3 public 'timezone' => string 'Europe/Wdoltown' (length=13) boolean true ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=52069&edit=1