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Posted by Jochem Maas on 11/13/59 11:22
Marcus Bointon wrote:
> I'm not sure if this is a bug or a feature, but it seems you can't use
> class constants to set default values for class properties. You can,
> however, use them for default values for method params, e.g.:
>
> class foo {}
^--- er.
> const BAR = 100;
> private $thing = self::BAR;
> function wibble($a = self::BAR) {
> echo $a;
> }
> }
class foo {
const BAR = 100;
private $thing = self::BAR;
function wibble($a = self::BAR) {
echo $a;
}
}
$f = new foo;
$f->wibble();
it _seems_ you did not test this, at least when I run this it gives me a fatal error
(which definitely leaves $this->thing undefined!)
>
> In this case $this->thing will be undefined, but wibble() will get the
> correct default value for $a.
>
> Comments?
I believe this is due to the fact that when setting up $thing, php is still building
the class definition therefore the constant does not 'exist' yet. the error msg I get
seems to confirm this.
this does work:
class qux { const BAR = 100; }
class foo {
const BAR = 100;
private $thing = qux::BAR;
function wibble($a = self::BAR) {
echo $a,"\n",$this->thing;
}
}
$f = new foo;
$f->wibble();
this does work, which really surprised me.
class foo {
const BAR = 100;
private $thing = foo::BAR;
function wibble($a = self::BAR) {
echo $a,"\n",$this->thing;
}
}
$f = new foo;
$f->wibble();
but honestly if you want to be very stricly correct about you OO then you
should not (I believe) be setting a value to an instance member in the class
definition, instead do:
class foo {
const BAR = 100;
function __construct() {
$this->thing = self::BAR;
}
function wibble($a = self::BAR) {
echo $a,"\n",$this->thing;
}
}
$f = new foo;
$f->wibble();
I tested all this on PHP 5.0.2 (cli) (built: Oct 21 2004 13:52:27)
>
> Marcus
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