问题:

Consider below code please:

class foo {
    function bar() {
        $this->baz = 'hello there!';
    }
}

$f = new foo;
$f->bar();
echo $f->baz; // hello there!

Why does above code work ? I mean I have not initialized the $baz variable and also I am not using __get and __set magic methods. I was expecting it would give me error, but it seems the $baz has been created and assigned public visibility. (BTW it does give error in static context though)

回答1:

Who told that you are not initialized,You have initialized by the statement $this->baz = 'hello there!'; This is how object oriented concept works.You are declaring a class , creating an instance for that class and then accessing that function and at last echoing a variable in that member function,This is how object orientation works...

回答2:

It's because how PHP works. If you set uninitialized property, it will be created even without __set. On the other hand, if you try to read uninitialized property, you end with warning.