在非静态方法中访问静态变量+继承

Question

I have the following stucture

class Foo
{
    public static $a = "parent";

    public static function Load()
    {
        return static::$a;
    }

    public function Update()
    {
        return self::$a; 
    }

}

class Bar extends Foo
{
    private static $a = "child";
}

I want the Update function to be able to return $a aswell, but I can't get it to work.

Bar::Load();  //returns child, Correct.
$bar = new Bar();
$bar->Update(); //returns parent, Wrong.

I've tried self:: , static:: and get_class() without success.

Answer 1

Change self::$a in update()

class Foo
{
    protected static $a = "parent"; // Notice this is now "protected"

    public function child()
    {
        return static::$a; 
    }

    public function parent()
    {
        return self::$a; 
    }
}

class Bar extends Foo
{
    protected static $a = "child"; // Notice this is now "protected"
}

$bar = new Bar();
print $bar->child() . "
";
print $bar->parent() . "
";