Re: PHP 4.0 Bug #4614: Empty strings are also considered as NULL

In PHP 3.0, there is no NULL. NULL is just a bad way to write "NULL", and thus, "" != "NULL". In PHP 4.0, NULL has a special value, similar to the SQL NULL. Still, with auto type conversion, NULL==0. As Andrei said, if you want to compare with NULL, you would usually want to use ===, which is an equality operator that does not do type conversions. Zeev On 26 May 2000 stephane.legrand@bigfoot.com wrote: > From: stephane.legrand@bigfoot.com > Operating system: FreeBSD > PHP version: 4.0.0 Release > PHP Bug Type: Other > Bug description: Empty strings are also considered as NULL > > <? > $test = ""; > if ($test == NULL) { > print("test is NULL <br>\n"); > } > ?> > > With PHP4, this code displays "test is NULL". > With PHP3, this code displays nothing. > > - it seems to me that PHP3 has a far more logical behaviour. > - i think it can be a big incompatibility problem between PHP3 and PHP4. > > So, is it a bug or a feature ? And is there a way to force PHP4 to act like PHP3 in this > particular case ? > > Thank you. > Stephane Legrand. > > > -- Zeev Suraski <zeev@zend.com> http://www.zend.com/