Re: Class constants

Gary . wrote: > On Mon, Apr 19, 2010 at 3:12 PM, Ashley Sheridan wrote: >> On 19 April 2010 14:24, Gary wrote: > >>> Okay. Why not? > ... >> Class constants must be defined with static values, not variables. They are constants after >> all! If they relied on the value of a variable, surely that would mean that their own value might >> change, so they would just become regular variables not constants. a constant is something constant (doesn't change), something static is something static (persistently there, but may change) > Right. But in fact the only referenced values are *also* constant > (unless I'm completely misunderstanding the use of 'const'), so I > think it's a valid thing to want to do. I accept it doesn't seem to be > possible, I'm now curious as to the thinking behind it. > >> Is there a specific reason that you need to try and achieve this? > > Okay, well here's a more meaningful situation, perhaps: > class SomeTable > { > const TABLE_NAME = 'mytable'; > const SELECT = 'SELECT * FROM ' . MyTable::TABLE_NAME; > const INSERT = 'INSERT INTO ' . MyTable::TABLE_NAME ... > try public static $INSERT = 'INSERT INTO ' . MyTable::$TABLE_NAME ... self::$INSERT > If the table name should change for some reason, it is preferable to > make the change in one place in the code (i.e. the value of > TABLE_NAME), surely, than changing the name in the alternative, which > is something like: > class SomeTable > { > // const TABLE_NAME = 'mytable'; > const SELECT = 'SELECT * FROM mytable'; > const INSERT = 'INSERT INTO mytable...