由於某種原因(哪個?),子類中定義的PHP常量/靜態變量在父類中不可用於靜態上下文中。通過父類在靜態上下文中不可用的PHP常量/靜態變量
爲什麼?
例1:
class Model{
function getAll(){
$query = "SELECT * FROM " . self::DATABASE_TABLE_NAME;
// ...
}
}
class Post extends Model{
const DATABASE_TABLE_NAME = 'post';
}
$p = Post::getAll();
當我跑,我得到:
Fatal error: Undefined class constant 'DATABASE_TABLE_NAME' on line 3
(以$查詢行= ...)
例2:
class Model{
function getAll(){
$query = "SELECT * FROM " . self::$DATABASE_TABLE_NAME;
// ...
}
}
class Post extends Model{
static $DATABASE_TABLE_NAME = 'post';
}
$p = Post::getAll();
然後我得到:
Fatal error: Access to undeclared static property: Model::$DATABASE_TABLE_NAME on line 3
(同一行)
因爲`self`指的是父母,其中常量或靜態變量沒有定義? – BoltClock 2011-02-16 17:44:20