php - Can't call static method from class as variable name? -

i'm using php 5.2.6. have strategy pattern, , strategies have static method. in class implements 1 of strategies, gets name of strategy class instantiate. however, wanted call 1 of static methods before instantiation, this:

$strnameofstrategyclass::staticmethod(); 

but gives t_paamayim_nekudotayim.

$> cat test.php  <?  interface strategyinterface {         public function execute();         public function getlog();         public static function getformatstring(); }   class strategya implements strategyinterface {         public function execute() {}         public function getlog() {}         public static function getformatstring() {} }  class strategyb implements strategyinterface {         public function execute() {}         public function getlog() {}         public static function getformatstring() {} }  class implementation {         public function __construct( strategyinterface $strategy ) {                 $strformat = $strategy::getformatstring();         } }  $objimplementation = & new implementation("strategyb") ;  $> php test.php  parse error: syntax error, unexpected t_paamayim_nekudotayim in /var/www/test.php on line 24  $> php -v  php 5.2.6-1+lenny9 suhosin-patch 0.9.6.2 (cli) (built: aug  4 2010 03:25:57) 

would work in 5.3?

yes. syntax introduced in 5.3

to workaround <= 5.2, can use call_user_func:

call_user_func(array($classname, $funcname), $arg1, $arg2, $arg3); 

or call_user_func_array:

call_user_func_array(array($classname, $funcname), array($arg1, $arg2, $arg3)); 

but on note, you're trying doesn't make sense...

why have static function? constructor in implementation expecting object anyway (that's strategyinterface $strategy looking for). passing string won't work, since strings don't implement interfaces. do, make interface non-static, , like:

$strategy = new strategyb(); $implementation = new implementation($strategy); 

then, in constructor:

$strformat = $strategy->getformatstring(); 

or, if still want method static do:

$strformat = call_user_func(array(get_class($strategy), 'getformatstring')); 

oh, , = & new synax deprecated (and doesn't think anyway).