Call a function while setting class properties

问题:

Is accessing functions while setting class properties possible in PHP (5.2 or 5.3) ?

class DAOClass {

   var $someProperty = SomeObject::staticMethod('readConfigProperty');

}

回答1:

It is not possible because you have to initialize the properties with constant values. It isn't even possible to do this:

var $property = array(0);

The way to do what you want to do is inside the class constructor:

class DAOClass {

    var $someProperty;

    public function __construct() {
         $this->someProperty = SomeObject::staticMethod('readConfigProperty');
    }
}

As a side note, using var to declare properties is not the preferred way. Use private, protected or public instead to declare a property along with its visibility (var defaults to public).

回答2:

No. In the class declaration you define properties. You do not assign them anything. Everything after the = must be a literal constant. Method/function calls are expressions and cannot be used there.