context of self

When I see a 'self' automatically to think of static methods. Lately I have been pointed out that self depends on the context. Just like 'parent', which can also call static methods. Consider this example:

error_reporting(-1);

class A
{
    public $var = 1;

    public function __construct($n)
    {
  开发者_开发技巧      $this->var = $n;

        self::foo();
    }

    public function foo()
    {
        echo $this->var;
    }
}

$obj = new A(5);

Operate without errors and within the method foo $ this is available. Someone can tell me some guide that explains in detail how the calls are resolved by self and parent?

---

$this $is a reference to the current object, while self is the reference to the class where it is used.

An example - the result of the code below is: (B::func)(A::func).

class A {
    function call() {
        $this->func();
        self::func();
    }

    function func() {
        echo '(A::func)';
    }
}

class B extends A {
    function func() {
        echo '(B::func)';
    }
}

$b = new B();
$b->call();